Winning in Ukraine won’t be cheap, materially or politically. The United States will need to spend more than the $14 billion that Congress committed to Ukraine last month to achieve all these aims. It will need to pressure its allies in Europe. And it will have to manage more nuclear saber rattling from Moscow by sending clear messages about what Washington will do if Putin resorts to using nuclear weapons in Ukraine, rather than constraining itself by promising not to take certain steps.

Although the United States must consider Moscow’s nuclear capacity as it formulates policy, the country cannot be deterred by Putin’s bluffs, as it sadly has been. (The Biden administration, for instance, ruled out sending MiGs to Ukraine as too “provocative.”) It is dangerous if the Russian president believes he can use these weapons to intimidate the United States from defending its allies and interests, especially because Putin’s objectives go well beyond establishing control in Ukraine. In his long speech before launching the February 24 offensive, Russia’s president made clear that he would like to have sway over all the states in the former Soviet Union, including NATO members in the Baltics. If Putin can successfully frighten the United States and win in Ukraine, he will feel emboldened. The likelihood of a Russian offensive against a NATO member will then increase significantly, as will the risks of an even greater international catastrophe. The costs of defeating Putin in Ukraine may be high, but they are far lower—and far less risky—than the costs of defeating him in Estonia…

Creating more “frozen conflicts” (which are never actually frozen) is not the answer in Ukraine. The United States has a window of opportunity to shift the trajectory of the war in the country so that Russia is forced not just to stop but to fully retreat. This will require swift action and resolute vision, with a laser-beam focus on victory. Now is not the time for handwringing and timidity.