Opinion | We must stand by Ukraine

As a percentage of GDP, more than a dozen contact group members now provide more security assistance to Ukraine than the United States. And these investments in Ukraine return here at home, strengthening our defense industrial base and creating good jobs. Putin’s aggression has even fueled the very outcome he wanted to prevent: NATO is now bigger, stronger and more united than ever.

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

Ukraine’s success so far is a major strategic achievement, but its troops still face major challenges on the battlefield. Russian forces recently occupied part of the territory that was liberated by Ukraine earlier in the war, and Mr. Putin’s bombing of Ukraine’s power plants and other critical infrastructure is taking a painful toll. The Ukrainian people showed magnificent defiance, but they paid a high price for their freedom.

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

In recent months, the United States and its partners have ramped up even more military aid — including hundreds of thousands of new artillery missiles, additional air defense missiles, more armored vehicles and more air-to-ground munitions — to help blunt Russia’s manpower advantage. We allowed Ukraine to use ATACMS missiles within Russian borders, which helped Ukraine defend itself after North Korea’s intervention in the war. During the conflict, as conditions on the battlefield evolved and as our supplies and readiness requirements permitted, we scaled up aid at a pace that Ukrainian forces could absorb, linking each donation to training and maintenance.

But Russia is suffering huge losses – an average of 1,500 casualties a day – to capture small pieces 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 heavy losses for minimal gains, perhaps order a mobilization that causes domestic instability, or negotiate seriously with Ukraine to end its war.