The Afghan rebels have been able to strike at the heart of Afghanistan, i.e, the fortified capital city of Kabul, at will. Few months back they struck Kabul just before elections to spill fear in the minds of the Afghan people who wanted to vote. The Afghan rebels had openly threatened people to stay away from voting.
Now these rebels have been able to strike the NATO base in Kabul killing three foreign soldiers and also three local policemen. This is the base where Afghan forces are trained by US army men. The strike only confirms the fear of the US Afghan head about the impending defeat for US forces in Afghanistan.