Final answer:
Option (b), The Bush Doctrine, focusing on preemptive war, diverted U.S. efforts from Afghanistan to Iraq based on the belief Saddam Hussein possessed WMDs and might support terrorism.
Step-by-step explanation:
The Bush Doctrine, a paradigm shift in U.S. foreign policy, advanced the idea of preemptive war and was implemented following the September 11 terrorist attacks. While intended to enhance U.S. security, diverting military resources from Afghanistan to the invasion of Iraq in 2003 presented both strategic and practical consequences. Though the removal of Saddam Hussein from power was achieved, the subsequent insurgency, coupled with the absence of weapons of mass destruction (WMDs), raised questions regarding the administrative direction and its immediate and long-term efficacy in combating terrorism.
Despite the Bush administration's assertion that Saddam Hussein was developing WMDs and posed a terrorist threat potentially connected to Al Qaeda, subsequent investigations found no credible evidence supporting these claims. There was a considerable loss of life, financial cost, and a debatable impact on regional stability, possibly hindering the war on terrorism. Assessing the full effect of the Bush Doctrine on the U.S. war on terrorism involves complex and often polarizing viewpoints, with arguments both for and against its success and justification.