Opinion | We Must Stand by Ukraine

As a percentage of G.D.P., more than a dozen contact group members now provide more security assistance to Ukraine than the United States does. And these investments in Ukraine are delivering returns here at home, boosting our defense industrial base and creating good jobs. Mr. Putin’s aggression even spurred the very outcome he had sought to prevent: NATO is now bigger, stronger and more united than ever.

As a result, Ukraine has held off the second-largest military in the world — despite Mr. Putin’s reckless escalations and irresponsible nuclear saber rattling. Ukraine has fought brilliantly even as China, the second-largest economy in the world, has backed Mr. Putin; as Iran, the biggest state sponsor of terror in the world, has armed him with missiles and drones; and as North Korea, the most notorious nuclear-armed rogue state in the world, has supplied him with ammunition and some 10,000 troops.

Ukraine’s success to date is a huge strategic achievement, but its troops still face profound challenges on the battlefield. Russian forces have recently clawed back some of the territory that Ukraine liberated earlier in the war, and Mr. Putin’s bombardment of Ukraine’s power plants and other critical infrastructure is taking a harrowing toll. The Ukrainian people have shown magnificent defiance, but they have paid a steep price for their freedom.

Still, Ukraine’s vulnerabilities should not mask Mr. Putin’s own growing dilemmas.

In recent months, the United States and its partners have been surging even more military assistance — including hundreds of thousands more artillery rounds, additional missiles for air defense, more armored vehicles and more air-to-ground munitions — to Ukraine to help blunt Russia’s manpower advantage. We have allowed Ukraine to use ATACMS missiles inside Russia’s borders, which helped Ukraine defend itself after North Korea’s intervention in the war. Throughout the conflict, as conditions on the battlefield evolved, and as our stockpiles and readiness requirements allowed, we increased assistance at a pace that Ukraine’s forces could absorb, linking every donation with training and sustainment.

But Russia is suffering huge losses — an average of 1,500 casualties a day — to seize small slivers of territory. Russia has suffered more than 700,000 dead and injured since Mr. Putin began his war. Now he increasingly faces a painful dilemma: either endure high casualties for minimal gains, perhaps order a mobilization that triggers domestic instability, or negotiate seriously with Ukraine to end his war.