On Tuesday, Vladimir Putin threatened to nuke Ukraine over the deployment of America’s missile defense systems. “It is horrible to say and even horrible to think that, in response to the deployment of such facilities in Ukrainian territory, which cannot theoretically be ruled out, Russia could target its missile systems at Ukraine,” the outgoing Russian president said. “Imagine this just for a second.”

Talk about imagining things. Ukraine is not yet a member of NATO, and Washington has not asked Kiev to host missile shield facilities. Yet it’s not too hard for us to imagine that the Kremlin would raise the prospect of incinerating nearby countries. Putin has already threatened to obliterate Poland and the Czech Republic over their tentative agreements to host missile defense radars and interceptors.

We say missile defense is intended to stop Iran, but the Russians seem to think our ten-interceptor system is aimed only at them and that it can bring down every one of their almost 800 missiles. In order to convince us that we are the ones who are being duplicitous, Moscow is now saying that Iran poses no threat to anybody. Tuesday, Russian Foreign Minister Sergei Lavrov stated that the Iranians will need ten years to develop a long-range missile. “Our position is based on facts, and the facts are as follows: Iran, which is thought to be the main threat, does not have and will not have missiles from which one has to protect itself in the long term.”

Thanks, Sergei, but Iran hopes to put a satellite into orbit by next March and has been testing its intermediate-range missiles with distressing regularity. And just yesterday you said this: “We do not approve of Iran’s action in constantly demonstrating its intentions to develop its rocket sector and continue enriching uranium.”

So don’t look for consistency in Kremlin pronouncements. Russia, which is helping Iran arm itself with the ultimate weapon, does not want us to try to protect ourselves. In a campaign reminiscent of its efforts to stop the deployment of the Pershing missile in Europe in the 1980s, it is willing to say anything, no matter how ludicrous. It is, therefore, time for the Bush administration to stop trying to placate Putin and force him to make a choice: either accept missile defense in Europe or help us stop the Iranian nuclear weapons program. It is not surprising that he is trying to make inconsistent arguments to get whatever he wants, but it is not acceptable that we let him.

And one more thing. We need to tell Putin, in public, that he must stop threatening Ukraine—or others—with his nukes. And if he should continue, it is up to us to remind him of our ability and willingness to use all the weapons we possess. The best way to slide into worldwide war is to ignore autocrats when they make unprovoked threats of unimaginable devastation.