Looks like the pretense has been dropped in Moscow. According to NBC News, Vladimir Putin has asked the Russian parliament to approve a plan for military intervention in Ukraine:

Russian President Vladimir Putin has asked parliament for approval to use the country’s military in Ukraine, the Kremlin said in a statement Saturday.

Putin said the move is needed to protect ethnic Russians and the personnel of a Russian military base in Ukraine’s strategic region of Crimea. …

The statement said: “Due to the extraordinary situation in Ukraine and the threat to the lives of Russian citizens and compatriots, and the personnel staff of Russia’s military forces based in Ukraine (Crimea), according to international agreement … I submit a request to the Federation Council of the Federal Assembly of the Russian Federation for the use of military forces of the Russian Federation on the territory of Ukraine until the social and political situation in the country normalizes.”

This sounds a bit like closing the barn door after the horse has bolted. The request comes after Putin has already sent as many as 6,000 troops into Crimea:

Ukraine accused Russia of sending 6,000 additional troops into Crimea Saturday, deepening a crisis in which both sides accused each other of trying to destabilize the region.

Russia defended this move by claiming that the government in Kyiv tried to retake its Interior Ministry building in Crimea by force. Essentially, this boils down to the “Mom, he hit me back!” argument:

The situation on the ground became even murkier when Russia claimed that Kiev-backed gunmen had attempted to take over the Crimean Interior Ministry. There was no confirmation of such an action from other sources. Russia’s foreign ministry said people had been wounded, but gave no details.

“With decisive actions by self-defense groups, the attempt to seize the interior ministry building was averted. This confirms the desire of prominent political circles in Kiev to destabilize the peninsula,” it said in a statement Saturday.

Accusing the native government of a region of destabilizing a situation by attempting to push foreign troops off its soil is about the epitome of chutzpah. Putin’s claim is that ethnicity trumps sovereignty, a rather dangerous argument for him to make in the context of the Caucasus, for instance. That’s the pretext that practically everyone saw coming, though — or everyone except Christiane Amanpour and American intelligence.

What will the Obama administration do? As it turns out, one reason why Russia finds this such a low-risk scenario is because the US and UK convinced Ukraine to give up its leftover Soviet-era nuclear weapons in 1994. In exchange for its unilateral disarmament, the US and UK pledged to defend Ukraine’s territorial integrity against any aggression in a pact known as the Budapest Memorandum:

A treaty signed in 1994 by the US and Britain could pull both countries into a war to protect Ukraine if President Putin’s troops cross into the country.

Bill Clinton, John Major, Boris Yeltsin and Leonid Kuchma – the then-rulers of the USA, UK, Russia and Ukraine – agreed to the The Budapest Memorandum as part of the denuclearization of former Soviet republics after the dissolution of the Soviet Union.

Technically it means that if Russia has invaded Ukraine then it would be difficult for the US and Britain to avoid going to war. …

Sir Tony Brenton, who served as British Ambassador from 2004 to 2008, said that war could be an option ‘if we do conclude the [Budapest] Memorandum is legally binding.’

It promises to protect Ukraine’s borders, in return for Ukraine giving up its nuclear weapons.

Kiev has demanded the agreement is activated after insisting their borders had been violated.

In response Mr Brenton said in a BBC radio interview: ‘If indeed this is a Russian invasion of Crimea and if we do conclude the [Budapest] Memorandum is legally binding then it’s very difficult to avoid the conclusion that we’re going to go to war with Russia’.

This twenty-year-old treaty is getting a fresh look in the UK media … but so far, American media seems to have either forgotten about it or are ignorant of its existence. Until a reader e-mailed us the details, I didn’t recall it either. However, this is uncomfortably similar to the situation in Europe during the 1930s, when Western security assurances failed to keep another empire-builder from forcibly acquiring new territories — on the basis of ethnic and linguistic continuity, too.

Enforcing the Budapest Memorandum would be a nightmare, pitting the US and UK against Russian troops in eastern Europe all over again (which the Clinton administration should have considered at the time). A failure to enforce the Budapest Memorandum might be a bigger nightmare, though. If the West fails to meet its security obligations to Kyiv, then the rest of eastern Europe (and the Baltic states in particular) will know that the West won’t lift a finger to help them, either. Don’t expect the West’s writ to run far in the event of that kind of collapse.

Update: The Russian parliament unanimously approved Putin’s plans for military intervention.

Update: Apparently, the Crimean peninsula has a third interested party — Turkey. A late-eighteenth-century treaty gave Crimea to the Russians, but only under certain conditions:

In an article in last week’s Russian Pravda, it was noted that if Ukraine was divided, then the status of the Crimean Peninsula – returned to Ukraine in 1954 by Nikita Kruschev, would be open to discussion, and that would include Turkey having a say in the future of Crimea.

The reference to this claim is the “Küçük Kaynarca” (Karlowitz I) signed 230 years ago. As per this agreement, signed by the Russian Tsarina Catherine II on April 19, 1783, the Crimean Peninsula was taken away from the dominion of the Ottomans and handed over to Russia. However, one of the most important provisions of this treaty was the debarment of independence for the Peninsula and outlawing its submission to a third party: Should any such attempt be made, then Crimea would automatically have to be returned to the sovereignty of Turkey.

When Ukraine appeared as an independent nation following the disintegration of the USSR in 1991, Turkey acquired the right to claim the Peninsula back based on the Treaty of Küçük Kaynarca; however, this was not brought up by the Turgut Ozal administration of the time. Turkey was content with advocating for the rights of the Tatar minority living on the Crimean Peninsula.

If the Russians are suppressing the Tatars, which is the general impression at the moment, then Turkey might get a lot more interested in pushing Putin out of Crimea, too. There’s some history there that will fuel those passions:

On top of that, for the majority of Turkish people who are well-read in history, the Crimean land has a distinct place when compared with other Turkic Republics, because similar to Hitler’s “holocaust” against the Jews, Stalin carried out atrocities against the Crimean Turks. Stalin’s campaign of forced ethnic cleansing and the relocation of the Crimean Turks is still well-remembered.

The Turks have a few such episodes in their history, too, but since they refuse to acknowledge those, don’t expect them to humbly watch as Russians push Tatars under their wheels again.

Update: The Tatars reject the idea that the Crimean seizure of buildings came from a natural uprising of native Russians:

Asked whether it had been Russian military forces who had seized Crimea’s parliament and executive administration early Thursday morning, Refat Chubarov, the Tatar leader and deputy in the parliament, said it had been organized by military forces.

“If there are still people who still think that the building of the Crimean Council of Ministers and the building of the Crimean parliament were seized by either some form of self-organized militia or some other civilian group, I have no time for these people,” Mr. Chubarov said at a news conference.

“These buildings were seized by specially trained people acting on military orders,” he said.

Update: James Joyner has a good post up on the crisis:

Some smart hands are calling for taking this to the UN Security Council to force Russia to cast an embarrassing veto. I don’t have a strong opinion on that, even though I think Russia’s national interests here are going to outweigh such considerations. Further, even if Russia didn’t have veto power, I’m not at all persuaded that a united Ukraine—much less one that’s being held together despite the wishes of a geographically compact and easily separable minority nationality—is something worth American blood and treasure.

Additionally, this highlights my longstanding opposition to further NATO expansion. The closer we get to Russia’s borders, as with Georgia and Ukraine, the more likely confrontation exists. And I’m not prepared to consider the use of military force against either of those countries an attack on the United States.

Well, the Budapest Memorandum requires either the US or UK to take this to the UN, so that should be happening anyway. I agree on the rest of his points, but the problem is that we’ve already left the impression that we have guaranteed sovereignty and security in this region, NATO membership or not. This is what comes out of well-intentioned efforts to put denuclearization ahead of long-term strategic interests. The collapse of the Soviet Union was not the end of history, as this very clearly demonstrates.

I don’t want to see Americans going off to war to keep Crimea Ukrainian, either. But we shouldn’t make those promises without that kind of will and interest, and this demonstrates that our promises probably don’t mean much if met by force. Don’t be surprised to see others take this demonstration into account.

Update: In 2010, the Obama administration explicitly re-endorsed the “security assurances” of the Budapest Memorandum:

Both sides reaffirmed their shared vision of a world without nuclear weapons and pledged to work together to prevent proliferation and to realize the Nuclear Security Summit’s goal of securing all vulnerable nuclear materials. The U.S. recognized Ukraine’s unique contribution to nuclear disarmament and reconfirmed that the security assurances, recorded in the Budapest Memorandum with Ukraine of December 5, 1994, remain in effect.

That’s why Kyiv is asking the question today.