AP Photo

It's the moment we've all been waiting for: the launch of the "surge" against the Taliban in Afghanistan. And to judge by the enormous firepower Nato commanders have deployed for Operation Khanjar, or "sword strike", this time the Americans mean business.

Four thousand US marines, supported by a further 650 Afghan troops and supplied with the best equipment the American military can provide, have moved into the lower Helmand river valley with the intention of eradicating, once and for all, the threat posed by the Taliban.