Twenty-first century international relations will be dominated by dozens of states exercising military, economic, diplomatic and cultural power. This is not your father's world, dominated by the U.S., Europe and Japan. Nor is it a world dominated by two superpowers, as it was during the Cold War, or by one, as it was for a moment in the 1990s. Power will be found in many hands in many places diffuse, diverse, not concentrated, power.
The primary threat to peace and prosperity in this new era is not a push for dominance by any great power. Today's great powers are not all that great. Russia still has a mostly one-dimensional economy heavily dependent on oil, gas and minerals and is hobbled by corruption and a shrinking population. China is constrained by its enormous and aging population, large social needs and a top-heavy political system that is far less dynamic than the economy. India, too, is burdened by its numbers and poverty, along with inadequate infrastructure and often sclerotic government. Europe punches far below its weight, given its parochialism, its culture and the unresolved tensions between the pull of nationalism and the commitment to building a collective union. Japan is constrained by an aging society, an anachronistic political process and the burden of its history. Brazil and several other countries are on the verge of becoming a global force but are not quite there.
The world's most powerful countries may not always agree with the U.S., but rarely do they see it as implacably hostile or an impediment to their core objectives. U.S. relations with the principal powers of this era are for the most part good or at least good enough. As a result, the biggest external threats confronting the U.S. are the spread of nuclear materials and weapons, the possibility of pandemic disease, climate change, a breakdown in the functioning of the world's financial and trade systems in short, the dark side of globalization. Also of concern are medium-size hostile states (Iran and North Korea) that have access to weapons of mass destruction, and weak states (e.g., Pakistan, Somalia and Yemen) that are unable or unwilling to police their territory to ensure it is not used by terrorists, drug cartels or pirates.
So what should guide U.S. foreign policy? Democracy promotion, humanitarianism and counterterrorism all come up short. Democracy promotion can be difficult: it is one thing to oust authoritarian regimes; it's very different and more difficult to replace them with something demonstrably and enduringly better. Iraq and Afghanistan are both cautionary tales, given the great costs of occupation and nation building. Humanitarianism suffers from its potentially enormous call on American resources at a time that U.S. economic and military means are strained. Counterterrorism is also too narrow in scope and provides no guidance for dealing with many of today's global challenges.
The best idea out there is integration, which aims to develop rules and institutions to govern international relations and persuade other major powers to see that these rules are followed. But world-trade talks are stalled, and global-climate-change talks are in even worse shape. Agreement on how to denuclearize North Korea, prevent Iran's nuclearization and address global economic challenges (despite the G-20) is sharply limited. Integration is a good idea whose time is yet to come.
In principle, one could live with having no foreign policy doctrine, and no framework can provide guidance for every foreign policy choice. Nevertheless, a doctrine can help establish priorities and steer the allocation of resources. And a doctrine can send useful signals to allies, adversaries, the public and Congress.