During the last century, the United States was able to lead the free world because we had great power, and because we understood that leadership was not only about power. Democrats like Truman and Kennedy, and Republicans like Eisenhower and Reagan understood that we needed a strong military to meet Soviet power, but that we also needed a strong economy and strong democratic principles to counter the ideological challenge of Communism. Our power gave us the means to lead, but our example legitimized our leadership and made others wish to follow us.
We also were able to lead effectively because our allies knew that containment was not a Democratic or a Republican doctrine: it was an American doctrine. They could rely upon the United States to stand with them, no matter which party was in power. Today, after several years of a failed and divisive foreign policy based upon illusions and ideology, we need a new, bipartisan foreign policy rooted in reality and in the enduring values that unite us.
The democratic values that unite America and its allies are indeed enduring, but the realities we face in the 21st century are new. Never has the world experienced such a combination of global growth and environmental decline, technological change and dwindling global resources, the emergence of new great powers and of existential asymmetric security challenges. Globalization has eroded the significance of national boundaries: Many of the greatest challenges that face us-from jihadism to nuclear proliferation to global warming-do not face only us. Urgent problems that once were national are now global, and dangers that once came only from states, now come also from transnational mafias and extremist social movements-as well as from social trends, such as our excessive consumption of fossil fuels. The problems of the 21st century are not the problems of a nation: they are the problems of an interdependent global society.
