In all these areas--from the disruption of terror networks, to victory in Iraq, to the spread of freedom and hope in troubled regions--we need the support of our friends and allies. To draw that support, we must always be clear in our principles and willing to act. The only alternative to American leadership is a dramatically more dangerous and anxious world. Yet we also choose to lead because it is a privilege to serve the values that gave us birth. American leaders--from Roosevelt to Truman to Kennedy to Reagan--rejected isolation and retreat, because they knew that America is always more secure when freedom is on the march.