Last summer’s war in Georgia brought into sharp focus several key components of U.S. foreign policy in the post-Cold War period, and raised major questions about the future of U.S. relations with Russia, Georgia and most of the former Soviet region. The war was also a wake-up call (to those who may somehow have still been asleep): The post-Cold War period—a time marked by a prostrate Russia and virtually unchecked American power in the region—is over. In this new post-post-Cold War period, the challenge for U.S. policymakers is to craft a strategy that recognizes both the potential danger Russia poses to its neighbors and the limits to U.S. influence in the region—limits that have only grown tighter thanks to the ongoing global economic crisis.

The war has already forced the United States to take a more critical look at its relationships with both Georgia and Russia. That task fell to a Bush Administration as it was coming to an end. But the war also forces us to situate those challenges in the context of a triangular relationship between Russia, the United States and Europe, because the United States cannot formulate an effective policy toward Russia without the support of the Europeans. This task falls to the Obama Administration as it is just beginning.

Re-examining our relations with both Russia and Georgia in light of Europe will be a complicated undertaking, not least because of the diverse views toward Russia within the European Union. In general, the East European countries are far more concerned about an imperial Russia, while the West European countries are more concerned about maintaining economic and other ties with Russia, lest conflict push the European experiment beyond its breaking point. These differences are highlighted whenever the word “Georgia” is spoken within European Union council chambers. Many East European elites believe that NATO membership for Georgia (as well as Ukraine) should be fast-tracked; any other course of action would seem to reward Russian aggression and devalue NATO’s reputation. But most West European elites believe that this is the very last thing we should do, lest it catalyze another war over Georgia, something that couldn’t possibly end well.

If the European Union lacks a coherent Russia policy, Washington will be as hard-pressed as ever to give it one. We cannot “get tough” with Russia without a European partner, yet a failure to challenge Russia’s imperial appetites could lead to disasters down the road. In such a situation, wise policy avoids forcing the issue in either of two dangerous directions. That is where U.S. policy was—precariously nestled in the bosom of useful ambiguity—before the summer war. And that is where the Obama Administration should return it to, if it...