“Do prove that you are with us,” President Volodymyr Zelensky pleaded with the European Union on Tuesday. “Do prove that you will not let us go. Do prove that you indeed are Europeans, and then life will win over death and light will win over darkness.”

As they gave the brave Ukrainian leader a standing ovation from hundreds of miles away, even as they knew his life is in peril from Putin’s forces, which edge ever closer to Kyiv and ever closer to committing atrocities on thousands of innocents.

Lawmakers say they are helpless to stop an almost inevitable Russian onslaught — the argument against helping Ukraine is that by attacking Russia militarily, the United States risks an escalation that will lead to the deaths of millions, and inflame a madman with his finger on a nuclear trigger.

But as the translator broke down interpreting Zelensky’s words, it’s clear that sympathies, sanctions and sending military equipment are not enough. Hundreds are already dead, including at least 16 children. Missiles with increasing ferocity are leveling buildings. The Russians bombed a Holocaust memorial Tuesday.

Sanctions may have isolated Vladimir Putin, but if his deadly convoy pushes on, if he insists on committing mass murder against a sovereign country, we cannot morally stand by.

Perhaps it’s the no-fly zone Zelensky requested Tuesday. Maybe it’s targeted drone strikes on the worst of the Russian armaments. Maybe it’s covert operations, the use of proxy forces, aggressive cyberwarfare, acts of precision sabotage. There are measures short of an all-out counter invasion that we’re certain the Pentagon has been looking into. Moves that would call Putin’s bluff, bloody his nose, give the Ukrainian forces more time, have him think twice about moving forward.

Indeed, they are exactly the kinds of tactics that push the boundaries and gray the lines that Putin has deployed against the international community over several decades.

At the very least, Biden needs to stop saying with certainty that “we will not fight Russia,” as he’s done multiple times. Telegraphing exactly what we will and will not do gives Putin more time and flexibility to tighten his grip on Kyiv.

Global opinion has turned against Russia. Even erstwhile allies are horrified about where this is going. So far President Biden has shown admirable restraint, hurting Putin where he can and seeing if diplomacy — and the Ukrainians own amazing resolve — can win the day. But like Adolf Hitler and Joseph Stalin before him, Putin does not act rationally or with any care for human life.

And, like Hitler and Stalin before, history will judge harshly the nations that let him get away with it — and that’s us.