Russian President Vladimir Putin's brutal invasion of Ukraine is fundamentally unjust, as wars of choice invariably are. The civilized world is correct to condemn the subjugation of a weaker country by a stronger one.
But morality in foreign policy isn't confined to alignment with the proper values and abstract principles, however important those are. Putin has no right to be doing what he is doing and bears the ultimate responsibility for the ensuing bloodshed. Yet he does have the power to do it. Policies designed to help Ukraine must be judged not only by their intentions, but by their real-world consequences.
Ukraine is a sovereign nation. That gives its government a right to join alliances of its own choosing. That may not, however, be wise given certain unpleasant yet unavoidable circumstances. Russia, a more powerful country, opposes Ukrainian NATO membership. Moscow is willing to go to war to prevent it. The Western powers correctly objecting to Russia's incursions are not willing to pay the same costs to defend Ukraine; they have thus far not even been willing to let Ukraine into NATO. Ukraine is unlikely to win a war with Russia on its own and will sustain great casualties trying to defend itself.
What good does it do Ukraine for the U.S. and its allies to defend the principle that it can join an alliance, yet not confer upon it any of the benefits of this alliance, at the risk of a Russian invasion? This principle may be right and Russia wrong in a cosmic sense. But what moral good is achieved if Ukraine's exposure to a bloody war is heightened instead? Even if Putin has expansionist designs beyond simply keeping the West away from his doorstep, which he clearly does, NATO expansion or half-hearted talk thereof does not automatically become a good idea if there's no real willingness to defend Ukraine from a Kremlin attack.
Foreign policy can be informed by what is good and true, but it can never be truly moral if it cannot realistically accomplish its objectives. Predictably setting people up for death and destruction can never be moral, even with the right intentions in contrast with Putin's murderous ones.
It's a lesson a superpower with 20 years of wars that either failed or yielded ambiguous outcomes should learn. Sadly, Ukraine may learn it instead.