The memory of the Vietnam War is holding an increasingly powerful sway over President Obama and his White House team as they explore ways to avoid the surge of troops into Afghanistan urgently being demanded by the US military.

Mr Obama and his foreign policy circle have begun openly to use language born of the Vietnam disaster, such as “mission creep” and “quagmire”. It is a clear sign that the President harbours doubts about a deeper military commitment in Afghanistan. Vice-President Biden is leading calls for a change of plan, with a scaling back of troops in Afghanistan and a narrow focus instead on destroying al-Qaeda with increased aerial drone attacks in Pakistan. He has been warning for months against getting into a political and military “quagmire” in Afghanistan.

His warnings failed to prevail early this year when, after a major review, Mr Obama announced to great fanfare a new strategy: a classic counter-insurgency mission aimed at protecting the population and stabilising the central government. He also ordered the dispatch of 21,000 more US troops.

He has now ordered a major review of that very strategy and refused to heed the demand by General Stanley McChrystal, the US ground commander in Afghanistan, for an urgent increase in the number of troops. General McChrystal said that without more forces immediately the war could be lost within 12 months.

At the weekend Mr Obama appeared to distance himself from the counterinsurgency strategy that he had introduced in March, and emphasised that disrupting al-Qaeda was the “core goal” of the mission. He worried aloud about “mission creep” that moved away from fighting al-Qaeda — which does not have a large presence in Afghanistan — adding: “If it starts to drift away from that goal, then we may have a problem.”

One senior official, speaking to The Times, introduced the word “Vietnam” into a discussion of Afghanistan — a term that no one in the Bush White House dared to utter about the Iraq insurgency. The official made clear that there was no appetite inside the White House for a long-term military commitment in Afghanistan, and that if the mission was not succeeding within a year, “we will all have to sit down and decide whether the mission is still worth it”.

The official added: “We’re not trying to build a 51st state of the Union . . . the goal is to deny al-Qaeda a base. The idea that we are going to be there 10, 15, 20 years — that’s not in the cards that I see.”

Officials emphasise that Mr Obama wants to be cautious about sending more troops into a war that is now in its eighth year, and is thus considering all options — and could yet accede to General McChrystal’s demands. The greatest factor in the rethink is the unresolved Afghan election and the prospect of having a central government in Kabul regarded as illegitimate and corrupt.

Yet aides are also saying that the report by General McChrystal is now just “one input” of many under debate — a lukewarm response at best to the urgent exhortations of the ground commander.

Mr Obama therefore arrived at the UN General Assembly yesterday with the job of stiffening the resolve of Nato allies — but at a time when he is questioning his own strategy. Several diplomats spoke of their worries over what they saw as a White House “wobble” over Afghanistan.

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