NEW YORK (TheStreet) -- As the Obama administration continues to evaluate its next move in the Afghanistan war -- easily the most contentious and most fraught of its foreign-policy challenges -- a handful of defense contractors, many of them as contentious as war itself, have been vending to, and outsourcing for, the U.S. military for years.Some companies have seen a boost in their businesses as Afghanistan flares and the violence in Iraq persists, albeit at a lower level than in recent years. The list includes such heavyweights as the hardware providers Boeing ( BA), Textron ( TXT) and General Dynamics ( GD), as well as the giant engineering firm Fluor ( FLR). But it also includes smaller players like the truck-maker Oshkosh ( OSK) and the logistics firm DynCorp International ( DCP). Defense contracting has always been both profitable and controversial. Indeed, such concerns continued to dog DynCorp on Wednesday, when the company -- which provides bodyguards to diplomats working in hot spots around the world among many other security services -- acknowledged Wednesday that it may have broken laws established by the Foreign Corrupt Practices Act. But, of course, the enterprising defense industry will carry on. With the Obama administration seemingly on track to stay in Afghanistan no matter the cost, which military contractor stands to benefit the most from the Pentagon's business?