In a special report today, Guardian writers analyse America's long war following the publication last week of a Pentagon report outlining plans for battling global Islamist extremism.
The Quadrennial Defence Review - a major strategy review and the first since the September 11 attacks - sheds significant light on US defence chiefs' thoughts on the nature of conflict in the two decades ahead.
It envisages "long duration, complex operations ... waged simultaneously in multiple countries around the world" from north Africa to south-east Asia.
Smaller-scale and more flexible interventions than the 2003 invasion of Iraq will be more likely in the future, it says, and there will be more reliance on beefed-up US special forces, the numbers of which will increase by 15%.
The 92-page report says there will be more psychological operations units and better training in languages and cultures. The numbers of unmanned aerial drones - which can be used to assassinate terror suspects - will almost double, and there will be a new long-range bomber force.
Experts say the document calls for greater ties and involvement with Nato and other US allies. However, it is unclear whether this means the US is likely to be less unilateral - one analyst tells Richard Norton-Taylor the report assumes Britain will be closely tied to the US without having any influence on strategy.
The review - required every four years by Congress - has caused concern among European governments, and is sure to heighten concerns over a long-running "clash of civilisations".
The Guardian says it would be foolish for the US not to think about integrated strategies, but points to "questionable assumptions and dangers" in the US defence secretary Donald Rumsfeld's "bleak review" of the future.
"America's enemies may be ruthless, but are they really trying to destroy its way of life? Are Osama bin Laden and co truly on the same level as Hitler or Stalin?" the paper asks in its leader.
It says US dominance is "part of life, whether we like it or not", but adds that the review begs the question of whether the "longest war against terrorism is winnable in any real sense".
Elsewhere, Lawrence Korb, the assistant defence secretary in the Reagan administration, describes the review as a disappointment. He writes on Newsday.com:
Our [US] overstretched ground forces are reaching the breaking point. The Pentagon's weapons systems are not tailored to existing threats, the armed forces have more weapons on the drawing board than they can afford ... our nuclear posture is outdated.
The review also raises legal and diplomatic questions, for example over the increased use of drones to assassinate terrorists. If the US begins operating in more countries, there are certain to be tensions over sovereignty.
Some have concluded that the report is trying to rebrand the conflict against Islamist extremism, although it does not explicitly declare this intention.
It opens by saying "The United States is engaged in what will be a long war", and the phrase "long war" is used far more regularly than "war on terror" - so widely used since September 11.
The Open Democracy columnist Paul Rogers attacks the "long war" description, saying it is "hugely convenient in that it simplifies everything into 'them and us'."
In his article The world as a battlefield, he notes various changes of emphasis in strategy - for example, huge amounts of money are being found for 100 Stryker armoured transport vehicles because Humvees have been so vulnerable to roadside bombs in Iraq.
Rogers is struck by how much extra funding will be poured into lessening the isolation of soldiers from their families - a big issue for those on long deployments in Iraq.
But nobody seems sure how long the "long war" will be. The Observer's Jason Burke - an al-Qaida expert - has in the past described how Islamist extremists such as bin Laden see themselves as part of an open-ended "cosmic struggle".
Writing after the July 7 attacks in London, Burke said the best hope was that the war with Islamic extremists would last a "decade or so".
It is now clear from the military review that US defence chiefs are looking even further into the future.
