Canadian troops fighting Taliban militants in Afghanistan have stumbled across an unexpected and potent enemy - almost impenetrable forests of 10-feet-high marijuana plants. General Rick Hillier, chief of the Canadian defense staff, said on Thursday that Taliban fighters were using the forests as cover. In response, the crew of at least one armoured car had camouflaged their vehicle with marijuana. "The challenge is that marijuana plants absorb energy, heat very readily. It's very difficult to penetrate with thermal devices ... and as a result you really have to be careful that the Taliban don't dodge in and out of those...
