This is worth reading in full. My favorite segment:
The progress of liberty is a powerful trend. Yet, we also know that liberty, if not defended, can be lost. The success of freedom is not determined by some dialectic of history. By definition, the success of freedom rests upon the choices and the courage of free peoples, and upon their willingness to sacrifice. In the trenches of World War I, through a two-front war in the 1940s, the difficult battles of Korea and Vietnam, and in missions of rescue and liberation on nearly every continent, Americans have amply displayed our willingness to sacrifice for liberty.The sacrifices of Americans have not always been recognized or appreciated, yet they have been worthwhile. Because we and our allies were steadfast, Germany and Japan are democratic nations that no longer threaten the world. A global nuclear standoff with the Soviet Union ended peacefully -- as did the Soviet Union. The nations of Europe are moving towards unity, not dividing into armed camps and descending into genocide. Every nation has learned, or should have learned, an important lesson: Freedom is worth fighting for, dying for, and standing for -- and the advance of freedom leads to peace.