But the short answer is this is pretty much all the GOP has. Want to claim that Obama has been soft on terror? That whole killing Osama bin Laden thing makes that a bit tough. Same goes for all the al Qaeda lieutenants who have been killed in drone strikes. What about pulling out of Iraq? Good luck finding many Americans who disagree with that decision. How about Afghanistan and Obama's call to begin pulling out troops in 2014? First, it's hard to argue that Obama didn't give war a chance in the Hindu Kush; second, Afghanistan is a less and less popular war every day. How about the claim that Obama has thrown Israel under the bus vis-à-vis the Palestinians? That's not going to make all that much of a difference. It turns out the two groups of voters most concerned about Israel (American Jews and evangelical Christians) likely already have a pretty clear sense whom they'll be voting for in November.
On the matter of reducing the defense budget -- a dicey proposition in an election year -- by getting Republicans to agree to military spending cuts as part of the debt limit deal, Obama largely neutralized GOP attacks on the issue. And it's not as if many Americans desperately want to see military spending significantly increased in an age of political austerity.
In the end, since there is no good near-term solution for stopping Iran from getting a bomb -- and since Iran continues to engage in provocative behavior like threatening for the umpteenth time to close the Straits of Hormuz -- it is the one issue that Republicans can try to pin on the Democratic president, claiming he is weak on national security.
In the end, however, such accusations are unlikely to have much staying power. As Scott Clement points out, even Republicans prefer diplomacy over the use of military force. In fact, compare the Obama approach to Iran (diplomacy, a regional security architecture, likely covert action, and crippling economic sanctions) with the Republican approach (diplomacy, a regional security architecture, likely covert action, and crippling economic sanctions). There really isn't much of a difference, except for the threatened use of force and all the doomsday talk. But it's there that the GOP rhetoric could have severe consequences.
As Republicans rattle their sabers this winter, they risk locking themselves into a dangerous position on Iran, should one actually win in November. Just ask Obama how pledging to devote more resources to the fight in Afghanistan in 2008 played out for his presidency.
With Romney et al. declaring that Iran will not get a nuke while they are president and with pledges of support for unilateral action on the part of Israel -- including the use of military force -- to stop Tehran from getting a bomb, Republicans may find themselves stuck with a dangerous policy on Iran that smacks of brinksmanship. Moreover, all the tough talk on Iran will also limit Obama's ability to open negotiations with Tehran over its nuclear program if the opportunity presents itself. Considering the increasingly desperate economic and political situation there, this might not necessarily be so far-fetched.
In the midst of a feisty presidential campaign, the Republicans' muscular rhetoric might seem a surefire way to create a political opening. But the ramifications of these existential threats have the potential to live on far past Election Day.