U.S.-Russian relations took a complex turn in late May.

On May 26, the U.S. State Department issued a statement declaring the Caucasus Emirate, a group led by Doku Umarov, a terrorist organization. “We stand in solidarity with the Russian people,” it said. Not only that, the State Department put its money where its mouth is, offering a reward of up to $5 million for actionable information about Umarov’s whereabouts.

It might seem a bit odd that the United States is offering a reward for the capture of a militant in Russia, but Umarov himself has declared the United States an enemy, along with Russia, Israel and Britain. The State Department statement, which also included a physical description of Umarov and e-mail addresses to contact, was no doubt welcomed by the Kremlin, which is often criticized for its brutality in combating Islamist insurgency in the North Caucasus.

A more important development concerned the conflict over NATO’s plan to place a missile shield over Europe. President Dmitry Medvedev has stressed that Russia could only participate in this venture as an “equal partner.” The United States wants NATO and Russia to establish separate but coordinated systems. That’s not enough for Russia, but as one senior European military official put it, “Realistically, the controls will be held by an American general in a NATO hat somewhere in Europe.”

On May 20, Russia’s top generals made what Time magazine called “a startling admission of weakness.” In their opinion, by 2015 the NATO missile defense system would neutralize both Russia’s ICBMs and its submarine-based ballistic missiles. That could be devastating for Russia because, as defense analyst Ruslan Pukhov points out, for “relatively little expense, Russia’s nuclear forces support the country’s status as a great power, provide a military deterrent to other major powers and enable it to maintain moderately sized conventional forces.”

But Pukhov also demonstrates that the generals are wrong about the 2015 date — or were just making noises as part of the bargaining process. Russia’s nuclear arsenal will not be significantly stymied by the system NATO wants to put in place. But once in place, that system could provide an excellent base for a more elaborate system that could indeed neutralize Russia as a nuclear power. Since Russia has no leverage over the United States and NATO, its only choice would be to upgrade its own heavy, ground-based multistage missiles. In other words, Russia and the United States, without in the least meaning to, may be backing into a new arms race.

And so the leaked nomination in late May of U.S. President Barack Obama’s top Russian adviser, Michael McFaul, to be the next ambassador to Russia was probably more than a matter of good timing. The Russians will be pleased to see the president’s own man in Moscow, a sign of the importance he ascribes to the relationship. McFaul, author of the “reset” policy, will provide the right blend of principles and practicality to keep the new relationship on track.

McFaul’s writings are quite critical of Putin, contending that any stability and economic progress in Russia came despite his authoritarian model. McFaul’s mandate may be to influence the Russian leadership to shift from the Putin model to the one identified with Medvedev. Obama, 49, McFaul, 47, and Medvedev, 45, are of the same generation, whereas Putin, 59, seemed more connected to an older time of suspicion and hostile competition, a time that could all too easily make a comeback. The stakes just got higher.