premise: Mr Fitzgibbon expects some of the 17,000 additional US troops heading for Afghanistan will bolster Australian forces operating in the dangerous Oruzgan province in the south. The defence minister was planning to raise the issue specifically with US Defence Secretary Robert Gates. He has already held talks with US central command chief General David Petraeus and director of the Central Intelligence Agency (CIA) Leon Panetta. General Petraeus discussed the new US strategy for Afghanistan and the troop surge in which an extra 17,000 troops will be deployed in the southern provinces where Taliban insurgents have been most active.
hypothesis: More troops are needed in the region.
reason: There is a troop surge because of need.