Quoting administration sources, the Washington Post reports that Russian troops have invaded Crimea, which is to say, sovereign Ukraine territory. Excerpt:

Earlier in the day, the new Ukrainian government said that hundreds of soldiers in green camouflage, without insignia but carrying military-style automatic rifles, had taken over two airports in Crimea. Regularly scheduled flights continued, at least until nightfall, when the airspace above Crimea, a region of Ukraine with deep ties to Russia, was suddenly declared closed.

Internet videos of Russian military helicopters flying over Crimea’s muddy winter fields went viral Friday. Russian IL-76 planes suspected of carrying 2,000 troops landed at a military base in Gvardiysky, near the regional capital of Simferopol, according to Crimea’s ATR television.

Russia’s Foreign Ministry said Moscow had informed Ukraine that it would be moving armored units from its Black Sea navy base in the city of Sevastopol deeper into Crimean territory to protect its operations.

In his remarks, Obama avoided confirming the Russian military movements. But U.S. officials said that confirmation of an influx of troops had prompted the president to speak.

“Any violation of Ukraine’s sovereignty and territorial integrity would be deeply destabilizing, which is not in the interests of Ukraine, Russia or Europe,” Obama said.

This is not good, but this is not surprising. Russia’s Black Sea fleet is based there. There is exactly zero chance that Moscow will give up military access to the Black Sea.

Meanwhile, here is a fresh report from Time, not — I repeat, not — The Onion:

In response to reports of a Russian takeover in parts of Crimea, Arizona Senator John McCain said on Friday, “We are all Ukrainians,” before calling for swift U.S. economic aid to Ukraine, condemnation of Russia at the United Nations, sanctions against Russian officials and the installation of U.S. missiles in the nearby Czech Republic.

No we are not. We are Americans. Let us mind America’s business. McCain actually wants to make war with Russia more likely:

On the military front, McCain believes Putin needs to face a show of U.S. strength. Putin is “convinced that the United States is weak and there’ll be no significant retaliation of his occupation of the Crimea and possibly eastern Ukraine,” he says. He wants to see Obama revive the Bush era missile defense plan, which would have placed U.S. missiles in the Czech Republic. He also believes that speeding up Georgia accession to NATO would send a strong message to Putin.

This is berserk. McCain used the same line in 2008 when the Georgian president started a fight with Russia, and got trounced. Ukraine has picked no fight with Russia, to be sure, but this is all happening not only on Russia’s doorstep, but in a region (Crimea) that has a deep and complex history with Russia, and that has only been officially attached to Ukraine since the 1950s, when Ukraine was part of the Soviet empire, and Khrushchev gave the peninsula to Ukraine. It is a serious provocation to Russia to bring Georgia into NATO; besides which, does America really want to risk nuclear war to defend a tiny, strategically unimportant country on Russia’s flank? Though Ukraine is vastly more important, strategically, it is unthinkable that the United States would risk war with Russia to prevent Moscow from seizing a heavily Russian peninsula that’s also a critically important naval base. Hell, the United States invaded Grenada on an infinitely flimsier pretext. McCain, then a US Representative, backed the invasion, saying it was important to “save American lives” — this, even though it was clear the US invaded to throw out Soviets and Cubans, and to send a signal to Moscow that its meddling in the US’s backyard was unwelcome.

Well, no doubt there is some Russian doppelganger of McCain preparing to praise Putin for saving Russian lives. It will be b.s., just as McCain’s praise of the US invasion of Grenada was b.s. (which is not to say the US invasion was wrong, from a geopolitical standpoint!). The point here simply is that Russia has vital interests in Crimea; the United States does not — and we must not let Ukrainian internal strife draw us into armed conflict. It is not our fight.

UPDATE: So now, the invasion is on. The BBC analyzes:

The choreography has been impressive. Within hours of the airport seizure, Russian MPs proposed a bill in the state Duma simplifying procedures for getting Russian passports to Ukrainians. The goal, the MPs said, was to protect a “brotherly nation”. Russia’s most important opposition leader, Alexei Navalny, meanwhile, has been placed under house arrest for two months and denied access to the internet. The Kremlin, that most risk-averse of entities, has everything covered.

It only remains to be seen what role Yanukovych will play in this fast-moving drama. Despite having fled the country, he insists that he is still Ukraine’s legitimate president. He is giving a press conference on Friday in the southern Russian town of Rostov-on-Don, close to the Ukrainian border.

This may seem like a bizarre provincial venue. But there is method here too: Russia refuses to recognise Kiev’s new pro-western interim government as a legitimate partner. It is likely to continue to treat Yanukovych – whose regime is accused of plundering $70bn (£42bn) from Ukraine’s treasury – as the head of a government-in-exile. It may even seek to return him to Crimea to continue his “executive” functions. Given Yanukovych’s love of bling, Crimea’s sumptuous Livadia Palace – where Stalin, Roosevelt and Churchill met to discuss Europe’s 1945 postwar carve-up – might serve as his new HQ.

More:

All of this presents the west with one of its biggest crises since the cold war. Russia has mounted a major land grab of a neighbouring sovereign state. How will the west react?

Not with military action, I pray. It’s clear what Putin is, but I can’t see how this threatens America’s vital interests.

UPDATE.2: The Crimean peninsula, upon which a major Russian naval base sits, is one thing, but if Putin invades the main territory of Ukraine, which it seems that he will, that’s quite another. I still don’t believe that a Western military response is wise at all, but Russia has to be made to feel pain some way. I think it would end up as a disaster for Putin, because Ukrainians will not roll over. The Russian Army is not the Soviet Army; I think the occupiers would face a lengthy and messy partisan war. Besides, nice pipelines you have running through Ukraine, Mr. Putin. Sure would be a shame if something happened to them.

UPDATE.3: A reader in Kiev points out that Russia has access to the Black Sea from elsewhere in its territory. Something else is going on.