Unfortunately, hope of a constructive relationship with Russia under Putin has vanished. A friendly rival has become, at best, an unfriendly adversary. Putin will not compromise his quest to dominate Russia’s sovereign neighbors (not least as a cynical way to build support at home for his corrupt and autocratic rule). He may play along with Western diplomats eager to avoid conflict, as happened recently in Geneva, but only as a way to consolidate his gains, divide the United States and Europe, play for time and prepare to push further. Western weakness emboldens Putin. The only thing he respects, and that can change his calculus, is greater strength.

We must make policy on this basis. In the short term, the United States must expand sanctions to major Russian banks, energy companies and other sectors of Russia’s economy — such as the arms industry — that serve as instruments of Putin’s foreign policy. We should also expose the most egregious corruption of Russian officials and cut off those people, their business associates and relatives from Western economies and travel. Some of our European allies may hope to avoid tough sanctions, but weak measures will not stop Putin, and the costs of doing so will only grow with time.

Ultimately, Putin’s actions in Ukraine require a strategic response. This does not mean a new Cold War. But it does require recognizing Putin’s geopolitical challenge to the post-Cold War order in Europe and preparing for a more competitive relationship with Russia.