In 2002 the Bush Administration unveiled a U.S. National Security Strategy that identified fragile states as a major security threat. It held that the weakness of certain states left power vacuums that could be exploited by transnational terrorist and/or criminal networks. Al-Qaeda's use of the Afghan countryside, to train and command those who attacked U.S. targets in September 2001, was framed as symptomatic of a larger problem. The War on Terror, pre-emptive defense, regime change and the integration of defence and development - became pillars of the U.S. response.