Soldiers' abduction adds to pressure for withdrawal

The search for the three missing American soldiers in Iraq potentially brings into conflict an irresistible force and an immovable object of warfare in the early 21st century: the ruthless fanaticism of al-Qa'ida pitted against the unshakeable determination of the US military to recover and bring back its own.

Though no firm proof is available, US commanders believe the men were abducted by al-Qa'ida or an affiliated group when their patrol was ambushed on Saturday at Mahmudiya, south of Baghdad. Four soldiers and an Iraqi interpreter were killed in the attack.

But their precise fate is uncertain. Though the umbrella insurgent group, Islamic State of Iraq, claimed it was holding the men, its posting on the internet provided no pictures of captives. Nor did it issue demands for their release, suggesting to some observers they may be already dead.

On past precedent, the chances of recovering the missing men are slim. A similar ambush near Yusufiya, north of Baghdad, last year led to the capture of two US soldiers. A four-day search involving 8,000 men had a grisly denouement when their bodies, bearing signs of torture, were found three miles away.

This time, once again, no effort is being spared. Major General William Caldwell, the chief US military spokesman in Baghdad, spoke emotionally yesterday of the "Soldier's Creed", whereby troops will do everything humanly possible to recover a comrade, be they missing, captured or dead.

The tradition is ingrained in the collective military psyche. An estimated 88,000 US troops are unaccounted for from the Second World War, the Korean War and Vietnam, and the Pentagon spends $100m (£50m) a year to find and recover their remains.

Normally, the US is adamantly opposed to having its troops used as pawns, and public opinion supports that stance. Many Americans were shocked by the spectacle of the British sailors and marines captured by an Iranian naval unit in March, and then paraded on Iranian television.

But the unpopularity of the war - which has already claimed almost 3,400 US lives - injects uncertainty into the equation. The presence of US troops in the middle of what is, to all practical purposes, a civil war is increasingly under question at home. The episode of the three soldiers could add to the pressure on the Bush administration to accept a timeline for withdrawal.

This, plainly, is the strategy of the insurgents. "Your soldiers are in our grip - if you want the safety of your soldiers, then do not search for them," the statement said. "We know you would have your entire army die, rather than have one crusader detained."

Earlier this month, Major General Rick Lynch, in charge of operations in the Mahmudiya region, described the war as "three-dimensional chess in the dark". There was "no simple solution" to a task that was "going to take a long time". The patience of ordinary American voters will surely be tested further by this latest abduction, whatever the outcome.