George F. Kennan celebrated his 100th birthday earlier this year. The dean of U.S. diplomats is best known for his strategy of containment, which he first articulated in the so-called long telegram that he sent from Moscow in 1946—and soon thereafter unveiled in his 1947 article, “The Sources of Soviet Conduct,” published under the pseudonym “X.” Several conferences honoring Kennan have praised his enormous contribution to U.S. Cold War strategy, yet the most fitting tribute would be to apply his seminal theories to our present era—to examine the sources of terrorist conduct.

Containing the Soviet Union and fighting terrorism are strikingly different undertakings. Kennan examined the behavior of a sovereign state with defined borders, an established populace, a recognized government, and an official ideology. Terrorism, by contrast, does not operate within clear boundaries or abide by diplomatic niceties. Containment cannot deal with such an elusive adversary. But neither is war a fully adequate concept for addressing terrorism as an ongoing challenge. Terror is the tactic, not the adversary itself. To deal with terrorism over the longer term, we must go beyond the symptoms of the problem to address its underlying causes—which is precisely where Kennan's strategic logic takes us.

In his X article, Kennan argued that Soviet power was the product of both ideology and circumstance. Russia's antipathy toward the West was born of historical insecurity. In that context, communism was less a goal than a means—a way for Moscow to maintain control at home and spread its influence abroad. “This means that truth is not a constant but is actually created, for all intents and purposes, by the Soviet leaders themselves,” Kennan wrote. “It is nothing absolute and immutable.” This observation led Kennan to two conclusions: First, the United States was engaged in a long-term struggle, because the Soviet leaders—confident in their ideological infallibility and secure in their belief of ultimate triumph—were in no hurry to achieve their goals. But, Kennan was quick to add, this messianic conviction did not mean the Soviets were necessarily committed to a do-or-die struggle to the end. He did not assume that Soviet ideology was so powerful that it could not be overcome, or that the zealotry of the present generation of leaders would necessarily be passed to the next. If the Western powers remained vigilant, Kennan believed, the Soviet system would inevitably turn inward to deal with its inherent contradictions.

Kennan was not soft on communism. His containment strategy targeted the Soviet regime, whose aggressive impulses had to be kept in check. But he also argued for a strategy of engagement with the Russian people, whom he refused to consider permanent U.S. enemies. Kennan later lamented that containment came to be seen in almost exclusively military terms; what he had in mind was the full range of economic, political, psychological, military, and cultural tools at the United States' disposal.

Today, the United States and its allies again confront a seemingly implacable adversary. The challenge is to address and understand the sources of terrorist conduct, even as we counter the efforts of those who would attack us. Like the Soviets before them, Islamic militants are a product of both ideology and circumstance. Although the militants can trace their ideas to strains of puritanical Islam from the 14th century and to the Wahhabi and Salafi movements of the 18th and 19th centuries, much of their pathology is unrelated to religion. Al Qaeda is, to a large extent, a symptom of social dislocation.

The benefits of economic globalization have largely bypassed Arab countries, even as it has exposed them as never before to outside influences. In oil-rich states, elites have used their wealth and power to maintain authoritarian rule and avoid economic and political reform. It is no surprise that the citizens of these countries view the outside world through the prism of exploitation. Meanwhile, the pervasive exposure to Western mass culture has served both to attract and alienate these societies. It's an old story: The more modern and dynamic society undermines the traditional society's values, practices, and allegiances. The recurring response to such an existential crisis is a surge in millenarian beliefs and an inclination toward nihilism. As has been the case in countless struggles before, terrorism is the quintessential weapon of the weak against the strong.

These conditions, however, need not be permanent. Hard as it may be to penetrate the anti-American sentiment prevalent in the Muslim world, the United States must undertake a strategy of engagement similar to what Kennan proposed for the Russian people. The two worlds are not as far apart as many think. A 2003 survey conducted by the Pew Research Center for the People and the Press reveals that citizens in Muslim countries place a high value on freedom of expression and the press, multiparty political systems, and equal treatment under the law.