Voice

The War Professor

Can Obama finally make the legal case for his war on terror?

I'm a law professor, but I generally avoid mentioning this to casual acquaintances, since they're apt to flee upon discovering it. They fear, I suppose, that I might at any moment launch into a tedious exegesis of the Uniform Commercial Code, or begin to elaborate on the fine distinctions between the law of armed conflict and the law concerning the use of force in national self-defense. So I try not to be the female law professor equivalent of "that guy." I try, in other words, to keep from boring everyone to tears with legal analysis.

But sometimes I just can't help it! Particularly when I hear government officials mangle, muddle, manipulate, and murkify the law, as I did at a Senate hearing on law and counterterrorism last week, I find that I just...can't...stop...myself. I have to start ranting and raving.

Because this stuff's important, okay? For some, it literally has life or death implications.

So bear with me while I rant.

On May 16, I testified at a Senate Armed Services Committee hearing. I described this above as a hearing on law and counterterrorism because I was trying to lead you into this gently, but technically, it was a hearing on the law of armed conflict, the use of military force, and the 2001 Authorization for Use of Military Force (AUMF). I know, even the description is snooze-inducing. But stay with me now. Four Pentagon representatives also offered testimony on the legal basis for U.S. targeted killings, but by the end of last week's hearing, I was more confused than ever about precisely what legal authorities the executive branch believes it possesses.

Normally, law professors thrive on confusion: We foment it in the classroom whenever possible. But while confusion is good for the law student soul, it's not so good for the executive branch of the U.S. government, and not so good for democracy or the rule of law.

Once upon a time, President Obama was a law student himself, and he later spent years lecturing at the University of Chicago Law School. He knows -- or certainly should know -- the importance of precision and clarity when it comes to the law.

On Thursday, Obama is set to give a speech at the National Defense University on U.S. counterterrorism policy. During that speech, he's widely expected to address the "legal framework under which we take action against terrorist threats, including the use of drones." It's about time. But will his remarks actually satisfy the rule-of-law concerns that I and many others have raised, or will they, like last week's Senate testimony, just increase the general sense of murk and muddle?

If President Obama were visiting my classroom, here are five questions I'd ask him.

1)      Mr. President, what -- if any -- limits do you believe the 2001 AUMF imposes on the use of military force, and what basis does Congress (or the public) have for evaluating whether your administration is respecting those limits?

On its face, the 2001 AUMF authorized the president to use force only against those responsible for the 9/11 attacks, and only for the purpose of preventing future attacks by such organizations against the United States. Yet the United States has reportedly used drone strikes to kill assorted "militants" and "extremists" who have no obvious link to 9/11 and no apparent likelihood of attacking the United States. (Case in point: the members of Somalia's al-Shabab.)

At last week's Senate hearing, administration representatives defended such strikes, distant as they appear to be from anything contemplated by Congress in 2001. In fact, they appeared to believe that the 2001 AUMF implicitly created an open-ended state of war that could potentially extend to al Qaeda's "associates" all around the globe. As long as the target is al Qaeda or its associates, they suggested, the president has, under the AUMF, the domestic legal authority not only to use drone strikes, but to send U.S. ground troops into combat in any country in the world without any additional authorization from Congress.

(Note: Senate hearings are matters of public record, but the full transcript currently remains behind a paywall. Sorry: Freedom isn't free! But if you're feeling really masochistic, you can watch the whole thing on video.)

Consider these exchanges:

When Sen. John McCain asked Acting DOD General Counsel Bob Taylor whether the 2001 AUMF could "be read to authorize lethal force against al Qaeda's associated forces" in countries such as Mali, Libya, and Syria, Taylor replied, "On the domestic law side, yes sir."

Sen. Lindsey Graham upped the ante: "Could we send military members into Yemen to strike against one of these organizations? Does the president have the authority to... put boots on the ground in Yemen?" Yes, Taylor responded, "Under domestic authority, he would have that authority."

Does the president have domestic legal authority to put boots on the ground in Congo, asked Graham? "Yes, sir, he does," responded Michael Sheehan, assistant secretary of defense for special operations and low intensity conflict.

In fact, asked Graham, "[W]e're talking about a world-wide struggle?... [And] the battlefield is wherever the enemy chooses to make it?" Taylor agreed: "Yes, sir, from Boston to the FATA [the Federally Administered Tribal Areas in Pakistan]."

Speaking not just as a law professor but as a citizen: It would be nice to know if President Obama thinks the AUMF authorizes him to use military force in Boston, wouldn't it? Not whether he would as a matter of policy refrain from using military force in Boston, but whether as a matter of law he believes that Congress has authorized him to use military force in Boston if "the enemy" turns up there.

When Senator Joseph Donnelly asked if the AUMF would permit the president to use military force inside Syria against the al-Nusra Front, however, Taylor seemed suddenly less sure: He agreed that al-Nusra is "an AQ affiliated group" but said, "I don't have a definite answer" on whether the AUMF would apply. His colleague on the panel, Assistant Secretary Sheehan, did have a definite answer: Under the AUMF, he said, "Yes sir, we'd have the authority to act against Al Nusra."

President Obama should tell us if he agrees that the 2001 AUMF gives him open-ended authorization to send U.S. troops into combat anywhere on Earth, as long as he asserts that their mission is to fight al Qaeda or "its associates." Or does he think there is some limit -- geographical, functional, or temporal -- on the scope of his authority under the AUMF? And: If there are some limits, how can Congress and the American public be sure his administration is abiding by those limits?

And, Mr. President? "Trust us, we have very careful procedures" is not the right answer here. Convince me that "checks and balances" refers to something other than the federal budget.

 

2)      Mr. President, exactly how do you define "associates" of al Qaeda and the Taliban? Is being "affiliated" with al Qaeda enough to make an individual or organization a lawful target under the AUMF, or must that person or organization do something more to become a lawful target? If so, what's the "something more"?

The main basis for AUMF mission creep has been the executive branch's assertion that the authority to use force against those responsible for 9/11 includes the implied authority to use force against their "associates." But who, exactly, counts as an "associated force"?

At the May 16 hearing, administration witnesses offered little clarity. Taylor, citing former DOD General Counsel Jeh Johnson, defined "associated force" as "first... an organized, armed group that has entered the fight alongside al Qaeda. And second... a co-belligerent with al Qaeda in hostilities against the United States or its coalition partners."

But this raises more questions than it answers. How organized is "organized," and outside of traditional, territorially-defined battlefields, what does it mean to "enter the fight" or be a "co-belligerent"? Outside of traditional battlefields, what constitutes "hostilities"? Does raising money for al Qaeda in Mali count as being a co-belligerent in hostilities, for instance? How about urging others to support al Qaeda?

Assistant Secretary Sheehan conceded that "mere sympathy" with al Qaeda is "not enough" to turn an individual or organization into an "associate," but other than that, there seemed to be no consensus on what makes a group targetable under the AUMF.

Perhaps hoping to deduce the administration's legal criteria from its conclusions, Sen. Carl Levin asked Sheehan if there's "any good reason why both Congress and the public should not be informed of which organizations and entities the administration has determined to be co-belligerents of al Qaeda?"

Sheehan responded with visible unease: "A lot of these groups, as you know, Senator, have very murky membership, and they all [inaudible] -- and they change their name. And they lie and obfuscate their activities. So I think it would be difficult for the Congress to get involved in trying to track the designation of which are the affiliated forces."

Let me translate. For there to be an "associated force" of al Qaeda, there must be an "organized armed group," but it would apparently be unfeasible for the administration to identify such "organized" armed groups because we can't actually figure out what they are or who is in them.

Nevertheless, assured Sheehan, "We know when we evaluate these forces what they're up to, and we make that determination based on their co-belligerent status with al Qaeda and make our targeting decisions based on that criteria, rather than on the shifting nature of different groups and -- and their affiliations."

So, the targetability of a group is not actually a product of its "organized" groupness or its affiliations after all, but rests on its "co-belligerent status with al Qaeda," which is determined based on...something, presumably, but it's not clear what.

Attempting to get beyond this circular reasoning, Levin asked, "Is there an existing list of groups that are affiliated with al Qaeda?" Sheehan responded that he "wasn't sure" if there was "a list, per se," but that he was "very familiar with the organizations that we do consider right now are affiliated with al Qaeda, and I could provide you that list."

I'd like to see that list, too -- but it still wouldn't answer the original question: Does the administration believe that all organizations "affiliated" with al Qaeda are lawful targets under the 2001 AUMF?

Maybe, maybe not, suggested administration witnesses. Return to the discussion of whether the AUMF authorizes the United States to use force in Syria against the al-Nusra Front: Acting General Counsel Taylor hedged, but Assistant Secretary Sheehan said yes, "we'd have the ability to act against al-Nusra. If we felt they were threatening our security."

So, wondered Sen. Donnelly, "Do we feel today that al-Nusra is threatening our security?" Sheehan declined to answer: "I don't want to get in, in this setting, to the decision-making we have for how... we target."

That's wasn't the question, of course: The question was whether al-Nusra is a threat to U.S. security. Still, Donnelly shifted politely to a more generic query: "OK, if a terrorist group is AQ-affiliated, does that inherently mean that they are threatening the United States?" To this, Sheehan answered, "Yes, sir, although it's a bit murky, I hate to say... in fact, as a government we haven't completely grappled with that as of now."

President Obama, this would be a good time to grapple with that question, wouldn't it?

Sheehan added one more comment: "Senator, you ask a good question because when a group aligns itself with al Qaeda, and al Qaeda has an expressed intent to attack Americans home and abroad, but then do not take the next step to be involved in that co-belligerency, then we have a judgment to make."

President Obama should tell us what this means. Beyond "affiliation" with al Qaeda, what would constitute a "next step" towards co-belligerency? Is that next step legally required before we can target a group under the AUMF? On what basis would we make "a judgment" about using force?

 

3)      Mr. President, if Congress amended the 2001 AUMF tomorrow to apply only to actions taken inside the borders of Afghanistan, do you believe you would still have the inherent constitutional power (and right under international law) to use military force to protect the United States against terrorist threats? If so, why do you need the AUMF? What, if any, uses of military force are you currently undertaking that you believe are lawful under the existing AUMF but would not be lawful if they were premised only on your inherent constitutional powers?

Administration witnesses at last week's Senate hearing suggested that congressional repeal of the AUMF would substantially reduce their ability to use military force, albeit in an unspecified way. Responding to a question from Sen. Jack Reed, Acting DOD General Counsel Bob Taylor noted that "the AUMF is our domestic law authority for considering ourselves to be in armed conflict with al Qaeda, the Taliban, and associated forces. So if the AUMF were to be repealed, I -- we would not be in an armed conflict."

What would this mean? Well, said Taylor, "It would absolutely affect our Title 10 authorities." (That is, authorities relating to the United States military, which are defined by Title 10 of the United States Code.)

So, asked Reed, would repealing the AUMF "operationally... have an effect on where you could strike and who you could strike?" Yes, responded Taylor, "it would." Reed went on to ask about so-called "signature strikes," and Taylor seemed to suggest that repealing the AUMF would "absolutely affect our ability to -- to engage in -- in those sorts of attacks."

But even as they appeared to suggest that an AUMF repeal would limit the president's ability to carry out at least some of the strikes he currently engages in, administration witnesses also asserted that the president has an inherent power to use force, AUMF or no AUMF.

If any new terrorist organization pops up in the future that has no connection to al Qaeda but still poses an imminent threat to the United States, Sheehan told Levin, "We would have other authorities to deal with that situation. I was in the government prior to 9/11 when we conducted strikes against groups before we had the AUMF, a specific post-9/11 authority. So we could use other authorities to take on those types of organizations."

Taylor reiterated this in response to a question from Sen. Mark Udall: "Mr. Taylor, if I could turn to you, if the United States faces an imminent threat in -- in -- to which Congress could not respond in a timely fashion, does the president of the United States have Article II authority to use military forces to repel an imminent threat to the safety of Americans?"

"Yes, sir, he does," responded Taylor.

Taylor and Sheehan are right: Every U.S. president has asserted such an inherent authority to use force, at least when faced with an imminent threat of attack, and neither Congress nor the judiciary generally disputes that the president has this authority. (Taylor later added, also correctly, that this inherent authority to use force to repel an imminent threat is also recognized under the international law of self-defense.)

Sen. Lindsey Graham asked Sheehan an even broader question: "Do you agree with me, Mr. Secretary, that the inherent authority of the president as commander in chief would give him or her great latitude in terms of pursuing terrorist organizations that represent a threat against the United States, apart from the Congress?"

"Yes, sir, I do agree," replied Sheehan.

So here's the question President Obama should answer: If his inherent Article II powers (and international law) already permit him to use military force not only against al Qaeda and its "associates" but against any group, linked to al Qaeda or not, that poses an imminent threat to the United States, why do we need the AUMF? Does the AUMF just formally give him Congress's blessing to do what he believes he can already do to counter al Qaeda and its associates, using his inherent powers, or does the AUMF give him some new power he thinks he would otherwise lack? What would that additional power be -- and why does he need it?

To put it a little differently, the administration has never been clear about whether it views its inherent self-defense powers as additional to those powers provided by the AUMF, or as an alternative basis for using military force in every situation in which force is currently being used.

This may seem like an arcane legal distinction, but it's not. As Taylor explained, the administration believes that the AUMF didn't just authorize "the use of force" -- it authorized the executive branch to commence an "armed conflict." There's a big difference. Not every use of armed force is part of a war, and not every use of armed force triggers "the law of armed conflict." (When the police use lethal force in the domestic law enforcement context, for instance, no one thinks they've started a literal "war on crime" or that the law of war applies to their actions.)

But when there is an armed conflict and the law of armed conflict comes into force, the international legal rules are quite different from those that govern the use of force in national self-defense. Basically, they're much more permissive with regard to the continued, ongoing use of force -- and much more flexible about who can be targeted, and when.

The law of armed conflict permits the targeting both of enemy combatants and their co-belligerents, and it also allows enemy combatants to be targeted by virtue of their status, rather than their activities: Under the law of armed conflict, you can target enemy combatants while they are sleeping, for instance, even though they pose no "imminent" threat, and the lowest-ranking enemy soldier can be targeted just as lawfully as the enemy's senior-most military leaders. Indeed, uniformed cooks and clerks with no combat responsibilities can be targeted along with combat troops.

In contrast, international law imposes criteria for the use of force in national self-defense that are more stringent than the criteria for using force in the course of an ongoing armed conflict. The international law of self-defense permits states to use force only to the extent necessary to respond to an armed attack or prevent an imminent armed attack. Under self-defense rules (unlike law of armed conflict rules) individuals who pose no imminent threat cannot be targeted, and the "necessity" requirement poses a fairly high threshold: It tends to restrict the use of force to strikes against those who -- by virtue of their operational seniority or hostile activities -- pose threats that are urgent and grave, rather than speculative, distant, or minor.

Most constitutional scholars also believe that the domestic legal rules that relate to using force are quite different when there's an ongoing armed conflict, compared to when there's no armed conflict. The Constitution gives Congress the power to declare war; raise, support, and make rules regulating the armed forces; make rules concerning "captures on land and water"; and call forth "the militia to execute the laws of the Union, suppress insurrections and repel invasions," as well as the power to "define and punish... offenses against the law of nations." The president, meanwhile, is constitutionally mandated to execute the laws Congress passes, and he's also the commander in chief of the armed forces.

Generally speaking, this means that when Congress authorizes an armed conflict, the president subsequently gets a relatively free hand in deciding how best to prevail in that conflict (subject to congressional rules regulating the armed force and to international law as defined by Congress).

But when Congress hasn't authorized an armed conflict, the president's constitutional power to use military force is more limited. He has a constitutional right (and, in fact, a constitutional obligation) to use military force to protect the United States from a threat so imminent and grave that it is not feasible for him to seek congressional authorization prior to using force, but that right to use force without congressional authorization declines as the threat dissipates and as it becomes feasible for Congress to act.

The Obama administration has told Congress that the threat from al Qaeda itself is far less grave today than it was in 2001. In fact, for all the talk about "new threats," the director of national intelligence told Congress in March 2013 that the only terrorist organization that might have the ability and will to attack the United States is al Qaeda in the Arabian Peninsula (AQAP), an AQ offshoot operating mostly in Yemen and Saudi Arabia. Even this group, he said, is likely more focused on regional mayhem than on attacking the United States.

The president has told us he doesn't want a "perpetual war." So, Mr. President: As the threat posed by al Qaeda dissipates and U.S. troops withdraw from Afghanistan, why isn't it appropriate for the United States to transition to a domestic (and international) legal framework in which there are tighter constraints on the use of military force? Why shouldn't Congress place a sunset clause into the AUMF? If new organizations emerge in the future and pose an imminent threat to the United States, why can't you rely on your inherent self-defense powers to use force, if needed -- or go to Congress and request a new AUMF that's specifically tailored to the new threat?

 

4)      Mr. President, exactly how will transferring drone strikes to the U.S. military ensure greater oversight and transparency? Are you willing to accept some external review of targeted killings by a court or an independent commission?

The "problem" with U.S. drone strikes outside hot battlefields isn't that some of the strikes are carried out by the CIA rather than the military -- the problem is the executive branch's assertion of what amounts to an unconstrained power to kill.

I've said it before, and I'll say it again: Given the secrecy shrouding U.S. targeted killings, the administration's legal justifications amount to an assertion that the executive branch has the right to kill any person, anywhere, at any time, based on criteria that remain secret and evidence that remains secret, evaluated by unknown people in a process that also remains secret, without any external review to prevent or remedy mistakes or abuses.

Unless these deeper rule-of-law problems are addressed, simply changing which government agency carries out targeted killings won't accomplish much. Yes, the military is subject to the law of armed conflict and the Uniform Code of Military Justice, and all things being equal, I have more faith in the military than in the CIA to abide scrupulously by the law. All things being equal, I'd also rather see the CIA stop the paramilitary stuff and get back to gathering and analyzing intelligence. But no one should imagine that "the military" is automatically more transparent that the CIA.

By law, "covert activities" must be reported to Congress's intelligence committees, but "covert activities" are defined to exclude "traditional military activities." If targeted killings are carried out by the military, the intelligence committees need not be informed, even if the targeted killings are secret and unacknowledged. And they don't necessarily have to be specifically authorized by -- or reported to -- the armed services committees, either. During an armed conflict, the president doesn't have to notify Congress of every strike against enemy forces. Thus, there's little reason to believe that shifting all drone strikes from the CIA to the military will address the deeper problems.

The president should be asked what measures he will take to ensure that drone strikes become more transparent if transferred entirely to the military. Given the existing secrecy surrounding the military's Joint Special Operations Command, which operates largely outside of the normal chain of command and normal reporting channels, he should specify what action he will take to enable greater congressional oversight and enhance public confidence.

Specifically, he should tell us whether he supports the creation of some external accountability mechanism in the form of a special commission or some sort of judicial review. In Israel -- one of our closest allies and a state with long (and unpretty) experience with targeted killing -- the Supreme Court decided, in a 2006 case, that targeted killings of terror suspects are subject to judicial review and independent investigation. Mr. President, is there any good reason for the United States to provide less accountability and fewer checks on executive power than the state of Israel?

 

5)      Mr. President, what are the international effects of U.S. drone policy, and what steps are you taking to evaluate and address those effects? Specifically, are U.S. drone strikes in Pakistan, Yemen, and elsewhere decreasing or increasing anti-American sentiment and the long-term risk of terrorism and anti-U.S. extremism? Is targeted-killing policy jeopardizing counterterrorism cooperation from allies and setting a dangerous precedent for adversaries?

Okay, these aren't legal questions, strictly speaking, but let's toss them into the mix anyway. Let's take administration officials at their word and assume that every single person targeted by drone strikes is a dangerous terrorist poised to attack the United States. It's still not clear that the expansion of U.S. drone strikes makes strategic sense. Civilian casualties can be minimized but not entirely avoided, and they cause intense grief and resentment in the communities in which they occur. Even when there are no civilian casualties, drone strikes can cause great resentment: Even dead terrorists leave behind grieving friends and families -- and those people are often ripe for terrorist recruitment themselves.

The president should be asked to explain whether and how he takes into account the possibility that targeted killings might be counterproductive in the long term. Has he directed his administration to assess changes in public opinion in regions and states in which drone strikes are occurring? What has he found, and what process exists for evaluating whether the strategic costs of drone strikes are outweighed by the benefits?

Here's another problem: The United States may consider itself in an ongoing global armed conflict with al Qaeda and its associates, but many U.S. allies consider this a legally dubious claim. Most of our European allies are subject to the European Convention on Human Rights, which can be enforced in their domestic courts. What will happen if a European court finds a U.S. drone strike to be unlawful? If European courts view U.S. targeted killings not as lawful acts during an armed conflict but as extrajudicial executions, how will this affect the willingness of U.S. allies to share the intelligence information that is often vital to targeting? More broadly, how will this affect their willingness to cooperate and assist the United States with a wide range of other activities?

Finally, the president should be asked to tell us what, if anything, will prevent U.S. legal rationales for targeted killing from being used and abused by repressive states. Let's say China decides to use military force to kill a Tibetan rights activist living in a Central Asian state. Let's assume the United States objects. What would stop China from responding that it considers itself to be in a state of armed conflict with certain Tibetan organizations and that it considers the killing of the activist lawful under the laws of war? Presumably, we would assert that no armed conflict exists -- and China would respond that a conflict does indeed exist, but that all evidence relating to the nature of the threat and the activities of the targeted activist is, regrettably, classified.

Mr. President, you're a lawyer, so help us out. Given U.S. targeted killings, what could we possibly say in response?

There's a Latin phrase all law students learn in their first-year torts class: Res ipsa loquitur. In English, "The thing speaks for itself."

CORRECTION: An earlier version of this article attributed the statement that AUMF authorizes the use of force against the al-Nusra Front to Brig. Gen. Richard Gross. That statement was in fact made by Assistant Secretary Sheehan, but was entered incorrectly in the congressional record.

Mark Wilson/Getty Images

National Security

The Electric Kool-Aid Flashback Test

Should we arm the Syrian rebels? America's attempts to do so in the past hold a few answers.

It's impossible to look at the Syrian conflict without horrified outrage, usually accompanied by a strong conviction that Somebody Ought to Do Something. But since "somebody" apparently doesn't extend to U.S. troops on the ground, Congress and the White House have turned instead to the idea that the United States might arm the Syrian opposition.

On the surface, it's an appealing idea. If a big, nasty dictator is crushing the plucky, outnumbered resistance fighters, let's give the little guys a hand! Arming the opposition would let us feel we're doing something "real" -- humanitarian assistance and diplomatic conferences being insufficiently dramatic -- without requiring us to risk deeper military entanglement in yet another Middle Eastern state.

But tempting as it is, past experience suggests that arming the Syrian opposition could be every bit as hazardous, difficult and uncertain as putting U.S. boots on the ground. Here are five reasons why:

1. Arming the Syrian opposition could end up placing weapons in the hands of terrorists.

To put it charitably, the Syrian opposition is decentralized. To put it less charitably but probably more accurately, it's fragmented and full of its own bitter internecine struggles. The Syrian National Council favors the creation civil democratic state; Jabhat al-Nusra favors al Qaeda's vicious version of Islam. That's not to speak of the others: left-wing secular groups, Kurdish separatists, and a multitude of other factions, large and small, each with its own agenda.

The United States is struggling to keep track of the players, a task complicated by our lack of cultural knowledge and "eyes on the ground," as well as by the protean nature the opposition. At times, individual opposition fighters and occasional entire organizations seem to shift their allegiance based on the shifting availability of money, supplies, and weapons. A May 8 report in the Guardian noted that the Free Syrian Army (FSA), the largest and most internationally credible opposition military group, has recently been losing fighters and sometimes "entire units" to the al Qaeda-linked al-Nusra Front.

To some extent, this trend has actually fueled arguments for arming the "moderate" Free Syrian Army: The logic is that if we don't arm the "good guys" in the opposition (the FSA, or parts thereof), the better armed and funded opposition bad guys (al-Nusra again) will soon come to dominate the rebel movement.

That's possible, but it's not clear that we even have the ability to provide weapons just to the "good guys." Even if we think we can identify "the good guys" within the opposition, and then ensure that weapons are delivered only to them, there's no guarantee that the good guys will remain the good guys (as opposed to taking their nice new U.S.-supplied weapons with them when they cross over to al-Nusra). And even if the good guys stay "good" in the short term, I wouldn't place bets on their long-term goodwill towards the United States.

Political loyalty is fleeting, but weapons, like diamonds, are forever. Near enough, anyway: Once weapons are out of our hands, it's hard to get them back -- and we have no guarantee that those weapons won't someday be used against us, years or even decades later.

Flashback: In the 1980s, the United States funded and armed the Afghan mujahideen fighting against the Soviet army and the Soviet-supported Afghan government. In part as a result of U.S. support for the Afghan insurgents, Afghanistan's communist regime was ultimately overthrown and the Soviets eventually withdrew all their forces. CIA officials clapped each other on the back.... Until the late 1990s, when we realized that many of the same mujahideen we had helped arm back in the 1980s had morphed into Taliban and al Qaeda fighters. By 2001, U.S. troops were facing those same mujahideen on the battlefield -- some of them armed with the same weapons we had given them for use against the Soviets.

2. U.S.-supplied weapons might not be used against the Assad regime.

Even if American weapons don't fall into the hands of terrorists or end up being used against us in some other way, they may not remain in the hands of those to whom we give them, or may be used for purposes other than we intended. Syria is full of the poor and the desperate, and weapons are valuable and high-prestige commodities. We should assume that many U.S.-supplied weapons will be given away as gifts, sold to the highest bidder, or simply appropriated for personal use.

Flashback: Missing weapons and ammunition have been a major problem dogging U.S. efforts in Afghanistan. Several years into the conflict, for instance, the United States decided to provide weapons to the Afghan Auxiliary Police. There was little vetting and little oversight, and some U.S.-supplied weapons found their way to the Taliban, while others were simply sold. The program ultimately became an embarrassment and was shut down. It took years for Washington to develop effective mechanisms for ensuring oversight and accountability for weapons distributed to Afghan forces.

3. U.S.-supplied weapons might be used to commit abuses.

Although the protection of Syrian civilians is a prime motivation for U.S. action, there's also a danger that American guns could end up being used to commit abuses. U.S. forces comply with the Geneva conventions and the laws of armed conflict, but we can't be confident that those we provide with weapons will all be as scrupulous.

We still don't know much about many key opposition leaders, but we do know that the opposition remains fragmented and there are few clear lines of authority within Syrian opposition forces. If U.S.-supplied weapons end up being used by splinter groups that torture, rape, or kill civilians, we'll look pretty bad -- and depending on the circumstances, we might even be deemed to share legal responsibility for any abuses.

Flashback: Nicaragua in the 1980s. Using U.S. weapons, the Nicaraguan Contras raped, pillaged, tortured, and killed, permanently tainting America's reputation in the region. Congress forbade the transfer of additional weapons or funds, and ensuing illegal White House efforts to arm the Contras led to the downfall and indictment of several senior Reagan administration officials. See also: El Salvador, Chile, Angola.

4. Adding more small arms to a volatile situation won't change any of the underlying political or military dynamics; it's more likely to prolong or fuel endless and indecisive conflict.

There's no shortage of small arms in Syria. On the contrary: The Syrian opposition is already awash in small arms, some provided by foreign backers, some seized from government stockpiles, others provided by defecting government troops, or simply taken from captured or dead government soldiers.

In and of itself, throwing more guns into the mix isn't likely to change anything significant. If anything, it will simply help prolong the conflict without really tipping the balance of power -- and the weapons we provide today will continue to fuel conflict in the years and decades to come.

Flashback: In Angola in the 1970s and 1980s, the United States backed (and armed) Jonas Savimbi's UNITA forces against the leftist MPLA. The war lasted for more than two decades, becoming one of Africa's longest, bloodiest, and most indecisive conflicts. Although Angola today lacks schools, hospitals, and a functioning economy, the country has no shortage of landmines or small arms. Some of the weapons originally provided to UNITA also found their way to other parts of Africa, from Sierra Leone and Liberia to the Congo, where they helped fuel new conflicts and enable new abuses.

5. To change the conflict's dynamics, we'd need to provide the opposition with heavy weapons -- but such weapons are only effective in the hands of well-trained troops.

More small arms won't help the Syrian opposition prevail against Assad's planes, tanks, and heavy artillery. If we want to see the Syrian rebels prevail, we'd need to provide them with over-match, in the form of heavy weapons. Providing such weapons to the Syrian opposition only doubles all the risks already mentioned -- weapons may end up in the wrong hands or be used to commit abuses.

On top of that, these weapons are unlikely to make a military difference unless we can also provide the Syrian military with extensive and thorough training and advising. As Colin Gray puts it, "weapons don't make war."

Unlike an AK-47, which is famously easy to use (so much so that it's been a major enabler of the recruitment of children into the world's conflicts), heavy weapons generally require operators with significant training and experience -- as well as troops with the discipline to use them effectively and appropriately in fast-moving combat situations.

This, in turn, means that we would have to make a commitment to advising and training the Syrian opposition -- something that's very difficult to do effectively without troops on the ground. We already have limited training facilities outside of Syria, but in the middle of an ongoing conflict, it's almost impossible for training to be thorough and effective when it takes place only briefly and far away from the battlefield. Effective commanders and fighters are understandably reluctant to leave the battlefield (and the country) for extended training periods. And when U.S. trainers are far away from the action, we have little ability to assess whether skills are successfully transferred to other fighters, and little ability to assess whether training is translating into effective tactical use of weapons on the ground.

Proceed with Caution

I don't mean to suggest that arming the Syrian opposition should be taken off the table entirely. But if we proceed, we should do so only with the utmost caution: After all, history suggests that U.S. efforts to arm insurgents tend not to end well.

Like so many global tragedies, this is one with no simple solution. It's a mess, and any "solution" will be messy, as well. But as with any proposed intervention with humanitarian motives, "do no harm" should be our first priority. If we can help, we should, even if there is some risk involved -- but if our actions are likely to just make things worse, we should refrain, painful as that is.

All of the above objections to arming the rebels could be addressed, in theory: Maybe we can adequately vet those to whom we provide weapons; maybe we can devise some adequate means to account for how and by whom weapons are used; maybe we can find means to ensure that weapons provided today won't be used against us tomorrow, or remain in the region to fuel new conflicts; maybe we can develop truly effective long-distance training and advisory programs. Arming the Syrian opposition would also raise many of the same international law problems as a direct military intervention, though this is a topic for another day. Here again, maybe we could also figure out how to overcome these legal obstacles.

But that's a whole lot of maybes.

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