Let’s be real. It’s one thing to say that Russia’s takeover of the Crimean Peninsula “cannot be allowed to stand,” as many foreign policy sages have proclaimed. It’s quite another to do something about it.

Is it just me, or does the rhetoric about the crisis in Ukraine sound as if all of Washington is suffering from amnesia? We’re supposed to be shocked — shocked! — that a great military power would cook up a pretext to invade a smaller, weaker nation? I’m sorry, but has everyone forgotten the unfortunate events in Iraq a few years ago?

My sentiments, to be clear, are with the legitimate Ukrainian government, not with the neo-imperialist regime in Russia. But the United States, frankly, has limited standing to insist on absolute respect for the territorial integrity of sovereign states.

Before Iraq there was Afghanistan, there was the Persian Gulf War, there was Panama, there was Grenada. And even as we condemn Moscow for its outrageous aggression, we reserve the right to fire deadly missiles into Pakistan, Yemen, Somalia and who knows where else.

None of this gives Russian President Vladimir Putin the right to pluck Crimea from the rest of Ukraine and effectively reincorporate the historic peninsula into the Russian empire. But it’s hard to base U.S. objections on principle — even if Putin’s claim that Russian nationals in Crimea were being threatened turn out to be as hollow as the Bush administration’s claim that Saddam Hussein had weapons of mass destruction.

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The Obama administration has been clear in its condemnation of Putin’s operation. Critics who blame the Russian action on “weak” or “feckless” U.S. foreign policy are being either cynical or clueless.

It is meaningless to rattle sabers if the whole world knows you have no intention of using them. There is no credible military threat by the United States that could conceivably force Putin to surrender Crimea if he doesn’t want to. Russia is much diminished from the Soviet era but remains a superpower whose nuclear arsenal poses an existential threat to any adversary. There are only a few nations that cannot be coerced by, say, the sudden appearance on the horizon of a U.S. aircraft carrier group. Russia is one of them.

If the goal is to persuade Russia to give back Crimea — which may or may not be possible — the first necessary step is to try to understand why Putin grabbed it in the first place.

When Ukraine emerged as a sovereign state from the breakup of the Soviet Union, it was agreed that the Russian navy would retain its bases on the Crimean Peninsula. After Viktor Yanu­kovych, Ukraine’s pro-Russian president, was deposed by a “people power” revolution last month, it was perhaps inevitable that Putin would believe the status of those bases was in question, if not under threat.

The new government in Kiev could offer formal reassurances about the naval base in Sevastopol. More broadly, however, Putin may have decided that allowing Ukraine to escape Moscow’s orbit was too much to swallow. Seizing Crimea does more than secure a warm-water port for Russian ships. It implies the threat of further territorial incursions — unless the new government in Kiev becomes more accommodating to its powerful neighbor.

This is not fair to Ukraine. But I don’t believe it helps the Ukrainians to pretend that there is a way to make Putin surrender Crimea if he wants to keep it.

The question is whether there is any way to tip the balance of Putin’s cost-benefit analysis. The Russian leader has nothing to fear from the U.N. Security Council, since Russia can veto any proposed action. Kicking Russia out of the Group of Eight leading industrialized nations would be a blow to Moscow’s prestige but probably would not cause Putin to lose much sleep.

Economic sanctions are more easily threatened than applied. The European Union depends on Russia for much of its natural gas — a fact that gives Putin considerable leverage. In a broader sense, there is zero enthusiasm in Europe for a reprise of the Cold War. Putin knows this.

If Putin really has lost touch with reality, as German Chancellor Angela Merkel reportedly speculated in a conversation with President Obama, then all bets are off. But if Putin is being smart, he will offer a solution: Russia gets sole or joint possession of Crimea. Ukraine and the other former Soviet republics remember that Moscow is watching, and we all settle down.

Sadly for Ukraine, but realistically, that may be a deal the world decides to accept.

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