Last November, the United States and its allies won a lopsided victory against the Taliban and Al Qaeda in Afghanistan. And then, shortly afterward, came a surprise attack—not in Afghanistan but in the Middle East. Militants there unleashed a fusillade of devastating suicide bombings in Israel. As Israel counterattacked, the Bush administration reluctantly turned away from Afghanistan—and Iraq—to face this new crisis.

No sooner did it do so than Islamic militants based in Kashmir and Pakistan struck in India. India responded by threatening war with Pakistan. Pakistan responded by shifting troops away from operations against Al Qaeda. The Americans, still hip-deep in the Middle East, now rushed to put out the fire over Kashmir. For a period of weeks, it appeared that the Kashmiri and Pakistani militants stood a respectable chance of not only distracting the United States but also starting a nice little nuclear war. That was their hope—and Al Qaeda's. "Al Qaeda and Taliban members are helping organize a terror campaign in Kashmir to foment conflict between India and Pakistan," reported USA Today.

Meanwhile, other Islamic militants attacked targets in Pakistan. These militants appeared to be linked to, or even subcontracting for, Al Qaeda. "Al Qaeda Tied to Attacks in Pakistan Cities; Militants Joining Forces Against Western Targets," said a Washington Post headline on May 30. "So many linkages," moaned one Pakistani observer quoted in the story.

Many linkages, indeed. In January, Israel intercepted a ship containing 50 tons of advanced weaponry, apparently purchased from Iran by the Palestinian Authority. The deal's intermediary and facilitator was none other than Hezbollah, a militant Islamic group that is second only to Al Qaeda in the number of Americans it has killed. On June 30, The Post reported that Hezbollah "is increasingly teaming up with Al Qaeda on logistics and training for terrorist operations, according to U.S. and European intelligence officials and terrorism experts."

What, exactly, is the United States up against here? Dozens of militant Islamic (or "Islamist") organizations operate in the shadows in dozens of countries, yet they seem uncannily adept at coordinating tag-team terror on multiple fronts. This is not just terrorism; it is terrorism with a foreign policy. It is not Islam as such, because most Muslims want nothing to do with it. It is not "Islamo-fascism," as some people have called it. Hitler, Mussolini, or Franco, who sought to elevate an all-powerful state above any religion, would regard Osama bin Laden—who seeks to elevate an all-powerful religion above any state—as a mortal enemy.

To understand the sort of war that militant Islam is waging, look not to the Far Right but the Far Left. This new adversary resembles an enemy America knows well: Marxism.

Of course, militant Islam differs from Marxism in many, many ways. Marxism comes from Europe, militant Islam from Arabia. The one is rooted in the Industrial Revolution, the other in the Middle Ages. One is atheistic, the other theocratic; one modern, the other anti-modern. The differences are too many and obvious to belabor. The very starkness of those differences, however, is what makes the movements' similarities so striking.

Both Marxism and Islamism are utopian, promising a future in which harmony, equity, and altruism will replace conflict, unfairness, and corruption. Both embrace historicism, the doctrine that ineluctable historical laws—economic in one case, divine in the other—make eventual triumph inevitable. Each is fundamentally anti-nationalist, hostile to the very notion of the nation-state; today's states and borders are illegitimate artifacts of an oppressive order, ultimately to be replaced by Communism or a Caliphate. Accordingly, both movements conceive of themselves as inherently internationalist, operating across borders as readily as within them. Though these movements regard seizing and using state power as essential, they do not want control of any particular government; they want control of the world.

Where they rule, Marxism and Islamism resemble fascism in their absolutist style. But they see state power not, in the fascistic way, as an end, but instead as a means: a stepping-stone toward a stateless future ruled directly by the masses or by God. Thus Marxism and militant Islam have little interest in joining coalitions and playing politics; where they cannot rule, they prefer to destabilize. Instability, in their view, can only help release the historical forces that operate in their favor. After all, capitalism (they believe) is fatally weak. Its strong exterior masks decadence and contradiction. All it needs is a hard push, and down it will go.

Given those ideological similarities, perhaps it is not so surprising that Marxism and militant Islam share some important structural characteristics. Both seek to burrow in where they do not rule, establishing cells whose grandiose conspiracies are sometimes farcical and sometimes deadly. Both claim to speak for the downtrodden but are in fact run by elite cadres drawn from the resentful fringes of a rising bourgeoisie. Both claim revered texts as their touchstones but never hesitate to reinterpret the texts according to the dictates of politics.

For ultimately, both have as their greatest asset—and perhaps their deepest similarity—a genius for disguising a brutal and self-serving political agenda as a quasi-religious mission of world salvation. Both claim not only to solve all political and social problems, but to answer all questions worth asking. Both thus inspire fanatical devotion worldwide. Each movement's local varieties are always idiosyncratic, but everywhere the followers recognize a commonality of interest. That shared interest is to tie down and harass the United States, to destabilize pro-American regimes, to foment class or religious conflict, and to weaken the capitalist West.

At the Cold War's height, American anti-Communists erred, sometimes laughably, in seeing the KGB or the hapless American Communist Party under every bed; but anti-anti-Communists were equally wrong to believe that, because there was no global Communist mastermind, there was no global Communist plot. Militant Islam certainly has its share of conspirators, but at bottom it is, like Marxism, a conspiracy of interests rather than of individuals. Smack it down in one place, and it pops up in another. As the United States has recently been discovering, Al Qaeda, Hezbollah, Jaish-e-Muhammad, Hamas, and the others require no coordinator to be effectively coordinated. They simply strike wherever opportunities for disruption present themselves.

Can they be beaten? In many respects, militant Islam is weaker than Marxism was in its heyday. Islamism lacks Left Bank glamour and enjoys no base of support among Western intellectuals (though the intellectual Left is mostly too flabby and confused to oppose it). Jose Padilla and Richard Reid notwithstanding, militant Islam may have a harder time than Communism recruiting insider help, because few Western Muslims and virtually no non-Muslims are sympathetic. Mercifully, the world has learned from the catastrophe of Communism to look with skepticism on utopian promises. Capitalism, too, is stronger and more humane than in the days of the robber barons and the Great Depression.

Above all, there is no Islamist Soviet Union, and none seems likely to appear. Islamists today control Iran and are seeking nuclear weapons there. They might yet take control of Pakistan, which already possesses nuclear weapons, and they would love to be the dominant force in a new Palestinian state. Still, not even control of Iran and Pakistan and Palestine—big headache though that might be—would give the Islamists anything like Soviet power. And they can expect setbacks. The loss of Iran, where their power appears to be waning, would be a serious blow, as would be (dare one hope?) the rise of a major Arab democracy in the Middle East.

When President Bush identified America's enemy as an "axis of evil," he missed by one vowel. He should have identified "axes of evil." Iraq, North Korea—and, for that matter, Syria and Libya and Myanmar (Burma)—are regime problems. One way or another, most of them are likely to be solved or mitigated by changes of government in the next two to 10 years.

In contrast, the Islamist axis that runs from Iran through Saudi Arabia, down through the Maghreb and the Middle East, on through the Stans of Central Asia and into scattered regions of Indonesia and the Far East—that axis is a 25- or possibly 50-year problem. It will have to be confronted and pushed back again and again, in many places. The skirmishes will be constant, complicated, far-flung, and exhausting. Which side will be exhausted first? Ask a Marxist—if you can find one.

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