By Paul Wood
BBC defence correspondent
The US patrol was hit just outside Falluja. Inside the city there have been almost no attacks since the coalition re-occupied it with a massive force of arms last year.
The focus of the war is expected to switch to Baghdad after the poll
But the effect of all the checkpoints, searches and barbed wire on Falluja's perimeter has been to push insurgent activity out into the countryside.
The 10 marines died while on foot patrol.
That is also a sign of how the marines have stepped up their counter-insurgency operations in the run-up to Iraq's elections on 15 December.
After those elections the focus of the war is expected to switch to Baghdad.
3 August 2005: 14 US Marines are killed in a roadside blast near Haditha, north-west of Baghdad
26 January 2005: 31 US Marines are killed when their helicopter comes down in bad weather in western Iraq
21 December 2004: 14 US troops are among at least 21 killed by a suicide bomber in a mess tent in Mosul
15 November 2003: 17 US soldiers are killed when their helicopters collide under heavy fire in Mosul
2 November 2003: At least 15 US troops are killed when their helicopter is shot down near Falluja
Instead of big search-and-destroy missions of the type still being conducted in western Iraq, the coalition will adopt the so-called "ink blotter" strategy.
It will seize, hold and control islands of territory which will expand and join up, just like drops of ink on a blotter.
The difficulties of this are shown by Ramadi, but the coalition has always had a presence, but then so too have the rebels.
Still, one unpublished estimate circulating among the US marines is that 30,000 insurgents have been killed since the coalition came to Iraq in 2003.
By that measure of bloody attrition, the coalition is winning.