Last July, more than 200,000 people flocked to a public park in Berlin to hear Barack Obama, then the Democratic candidate for president of the United States, deliver a speech calling for renewed transatlantic partnership and cooperation. The choice of Germany's long-divided capital as the backdrop for his only public speech in Europe was deliberate. Now that Obama is president, will Germany respond to the call and join the United States as a key European partner in addressing global challenges and threats?

Both countries would benefit from renewing their Atlantic partnership, but some formidable obstacles persist. The most important relationship Germany will have to navigate is that with Russia, with whom it has deep historical ties. Germany is Russia's largest trading partner and has become increasingly reliant on Russia's energy supplies, buying a third of its oil and gas from the country. There is a genuine military threat to Europe from Russia, as became clear in the August 2008 war between Georgia and Russia and in Russian President Dmitry Medvedev's threats to counter US missile defense plans by stationing Russian missiles in Kaliningrad.

But Berlin's pursuit of what German policymakers have insisted on labeling a "strategic partnership" with Moscow has put Germany in the middle of the evolving tensions between Russia and the West. It has also given Germany a unique responsibility. The old German question has long been solved, with Germany firmly positioned within Europe and the Western group of nations. But now, there is a new and similarly urgent German question for the twenty-first century: Is Germany able and willing to use its considerable political resources to change Russia's behavior and to stand up to Moscow when necessary?

The war in the Caucasus was a defining moment for German attitudes toward Russia, but there will be many more such moments in the months to come. Future challenges posed by Russia will thrust some hard choices on Germany's leadership. It is time for a new Ostpolitik for the post-Caucasus war era. But what is needed is a genuinely transformational scheme. This would require an across-the-board, rather than a bilateral, approach. Germany and the West should engage Russia broadly and imaginatively -- rather than grudgingly and selectively, as the Bush administration did -- and contain and counter it when necessary. As the conflict in Georgia showed, firmness and unity from Europe can go a long way, especially when backed up by the United States. EU members and the United States will all lose -- to Russia, mostly -- if they compete against one another in eastern Europe.

Such a comprehensive policy would by necessity be pan-European. But Germany should be its initiator and leader, not only because of its historical responsibility for Eastern Europe but also because its special relationship with Russia gives it greater weight and authority with Moscow than any other country on the continent. The future of Germany's legitimacy as a leader in Europe and as a partner for the United States -- not to mention the future of its soft power -- depends on its success in this role.

However, to take up this challenge, Germany will have to overcome an array of entrenched reflexes. It will have to:

1. Think of Eastern Europe as a zone of first-order strategic interest rather than as a disparate jumble of faraway countries.
2. Conceive of its foreign policy not in terms of constraints but in terms of choices.
3. Overcome its fear of dependency on Russia, recognizing that Russia needs its Western customers as much as they need Russia.
4. Understand that this new approach is not just about interests and strategy but also about solidarity, namely, defending the rights of countries that seek safety, prosperity, and democratic values and freedoms: the aspirations Obama spoke of in Berlin last summer and that the United States once protected in West Germany. To the extent that Russia acts to deny these essential rights, Germany and all of Europe must comprehend that they are being confronted with an authoritarian challenge to liberal Western democracy. For reasons of moral self-preservation as much as solidarity, balancing is then no longer an option. That, in the end, is the answer to the new German question.

Dr. Constanze Stelzenmüller is Director of the Berlin Office of the German Marshall Fund of the United States.

A longer version appeared first under the title "Germany's Russia Question - A New Ostpolitik for Europe" in Foreign Affairs (March/April 2009). This shortened version is published with permission from the author.