The US is worried about weakening Italian and German military commitments in Afghanistan as casualties increase in the fight to stem the bloody Taliban insurgency, officials said.
Debate has become intense in Italy and Germany, and to a lesser extent the Netherlands and Denmark, on whether they should remain in the International Security and Assistance Force (ISAF), which is already grappling with a shortage of troops in the face of one of the most intense military engagements in decades.
"There is a good prospect that we are going to lose some" contributions from certain countries, a US administration official said, as several European nations are scheduled to vote on their reconstruction, military and training commitments in Afghanistan.
The NATO-led 37-nation ISAF and a separate US-led coalition, with a total of around 50,000 foreign soldiers, are together with Afghan security forces fighting to block the return to power of the Taliban after the hardline Islamic militia was ousted in late 2001.
But with the fighting now peaking and more deaths among ISAF forces -- including the friendly fire incident on Friday that killed three British soldiers -- Washington is deeply worried about eroding support for the effort.
"It will be disappointing if there are fewer NATO partners that are involved in this mission," the US official said.
"Italy and Germany are the ones that are of serious concern," the official said.
With 2,500 troops, Italy heads NATO's Herat-based regional command in western Afghanistan.
Italian Foreign Minister Massimo D'Alema recently blamed a lack of coordination between US and ISAF forces for hundreds of Afghan civilian deaths, which he called "morally unacceptable."
"The Italians can be proud of what they are doing but at the end of the day it's not so much a referendum on `are we making a difference?' but really a referendum about how closely do you want to be associated with the US administration," the US official said.
In Germany, where polls show a strong 64 percent majority calling for withdrawal, parliament would have to vote on whether to continue with commitments for reconstruction, military deployment and training of Afghan forces.
The US is particularly worried about the military commitment.
"As the issue of civilian casualties becomes more and more an issue in German politics, that is another one that is of real concern," the US official said.
"And if the concerns are really high, that might spill over into the training of security forces," the official said.
Germany has lost 25 soldiers, three police officers and four civilians in Afghanistan since it began operations in Afghanistan in 2002.
The past month has been particularly grim with the abduction by the Taliban of two German engineers, one of whom was shot dead. The other is reportedly ill and begging for his life.
Germany has contributed some 3,000 troops to the NATO mission and has six Tornado reconnaissance planes helping to spot Taliban hideouts.
About 100 elite troops have a mandate to participate in the US-led anti-Taliban Operation Enduring Freedom, but are not deployed against insurgents in the south.
In the Netherlands, there is some unease about how long the Afghanistan effort will continue, but US officials believe cuts in the Dutch military deployment will be spared.