Critics of the Iraq war have called it George Bush's Vietnam. Now, it appears, President Bush himself agrees. In a speech to the Veterans of Foreign Wars last week, the president sought to increase support for his policy by drawing parallels between the consequences of the US departure from Indochina in the mid-1970s and possible consequences of a US withdrawal from Iraq. In Vietnam, the president stated, "the price of America's withdrawal was paid by millions of innocent citizens, whose agonies would add to our vocabulary new terms like boat people, re-education camps and killing fields". Similar suffering would follow from US withdrawal in the midst of continuing conflict in Iraq. In addition, the president argued, the US itself would lose much of its credibility and suffer a defeat in the global ideological struggle against jihadism.

Bush's evident purpose in making the speech was to win back the support of conservatives who consider the Vietnam war to have been a noble lost cause but are having growing doubts about the Iraq war. Even so, the assertions of President Bush deserve to be analysed on their merits.

About one thing the president is undoubtedly correct: Osama bin Laden and other jihadists would be emboldened by a US withdrawal. Doubtless they would take credit for having humbled the "world's only remaining superpower", even if Sunni and Shia insurgents who are not jihadists were primarily responsible for forcing the US out. The jihadists could point to the US withdrawal from Iraq, following Israel's withdrawal from Lebanon and the Soviet Union's withdrawal from Afghanistan, as proof that non-Muslim powers can be defeated by Islamic militants.

One of the lessons of the 20th century is that a revolutionary success in one or a few countries can inspire a transnational revolutionary "wave" because the revolution is seen as unstoppable. There were waves of international enthusiasm for communism, fascism and, in the 1950s and 1960s, revolutionary secular Arab nationalism. Perceived US defeat in Iraq could strengthen the contemporary wave of Sunni Muslim radicalism and make it more dangerous. Indeed, as the president pointed out, Bin Laden himself has cited Vietnam as evidence of America's weakness.

But the enemy is not the sole audience for displays of military credibility by a great power like the US. The other audience consists of allies and client states. Even if a defeat emboldens the enemy, it does not necessarily weaken the confidence of the defeated nation's allies and client states.

During the cold war, American statesmen were seriously concerned that US defeats in symbolic proxy wars with the Soviet bloc in Korea, Indochina and Afghanistan could lead major allies like West Germany and Japan to doubt the ability of the US to protect them and to appease the other superpower. But in the case of the jihadist revolution, there is no other superpower. There is not even a minor power on the other side. With the fall of the Taliban and Pakistan's alignment with the US after 9/11, al-Qaida lost its only state sponsors. It has no official support from the Sunni regimes it aims to topple, or from what it regards as the Shia heretics in Tehran.

In his speech, Bush said that the US efforts in Asia in the second world war and the cold war, like the campaign against jihadism, "are all ideological struggles". While imperial Japan sought to build an empire, not spread a creed, the cold war struggle was indeed both ideological and geopolitical. But the struggle against jihadists is almost purely ideological.

Here, the greatest difference between Vietnam and Iraq is apparent. When the US pulled out of Indochina, communists came to power in Vietnam, Laos and Cambodia. But if the US pulls out of Iraq, jihadists will not come to power there. Either a Shia majority regime will consolidate a new Iraqi state or de facto partition will result in three regions ruled by Shias, Sunnis and Kurds.

There is a genuine danger that al-Qaida could maintain bases in chaotic parts of Iraq. But the obvious solution is for the US to provide indirect help to the local authorities in crushing jihadist networks - which may well be some of the Sunni and Shia insurgents whom the US is now fighting. The goal of stamping out Bin Laden's allies in Iraq does not require the US to fight both sides in the Sunni-Shia ethnic war on behalf of a fictive national unity government.

There is no doubt the international jihadist movement will be emboldened by US withdrawal. But the jihadists will be unable to translate their jubilation into effective action if the US works with authorities in a post-American Iraq to suppress jihadists, and collaborates with other nations to heighten their homeland security measures.

The US cut its losses in Indochina, and went on to prevail in the cold war. In the same way, the US will cut its losses in Iraq - and then will go on with its allies to withstand and outlast the revolutionary jihadist wave. The defeat of the communist bloc was not a foregone conclusion. The eventual defeat and decline of jihadism is.



· Michael Lind is Whitehead senior fellow at the New America Foundation, and author of The American Way of Strategy newamerica.net