Sounds like Palin answered the question
Here is how Wiki defines the Bush Doctrine:
The Bush Doctrine is a phrase used to describe various related foreign policy principles of United States president George W. Bush, enunciated in the wake of the September 11, 2001 attacks. The phrase initially described the policy that the United States had the right to treat countries that harbor or give aid to terrorist groups as terrorists themselves, which was used to justify the invasion of Afghanistan. Later it came to include additional elements, including the controversial policy of preventive war, which held that the United States should depose foreign regimes that represented threat to the security of the United States, even if that threat was not immediate (used to justify the invasion of Iraq), a policy of supporting democracy around the world, especially in the Middle East, as a strategy for combating the spread of terrorism, and a willingness to pursue U.S. military interests in a unilateral way. Some of these policies were codified in a National Security Council text entitled the National Security Strategy of the United States published on September 20, 2002.
Doesn’t Gibson do research?