The American general who serves as Nato's military commander has warned that 10 member countries' refusal to send troops to Iraq for the alliance's new training mission threatens the long-term viability of the operation, making it difficult to find enough forces to serve in Baghdad.

More ominously, General James Jones, the supreme allied commander, Europe, said the block by the 10 nations, which he would not name, could undermine the alliance itself, which is already stretched by missions to Afghanistan and the Balkans.