American foreign policy has changed dramatically since September 11, 2001. Priorities have been altered, several importance bilateral relationships recast and, not least, the general tone of the still-new Bush Administration toward multilateral diplomacy has softened. In the words of President George H.W. Bush,“Just as Pearl Harbor awakened this country from the notion that we could somehow avoid the call of duty and defend freedom in Europe and Asia in World War II, so, too, should this most recent surprise attack erase the concept in some quarters that America can somehow go it alone in the fight against terrorism or in anything else for that matter.”
Nye, Jr., Joseph S. "Seven Tests: Between Concert and Unilateralism." The National Interest on International Law and Order. Ed. R. James Woolsey. Routledge, 2018, 77-87.