Almost certainly orchestrated by Vladimir Putin, Crimea's appeal to join Russia pits the president directly against the West in a standoff that has increasingly high stakes and unpredictable consequences.
The vote by Crimea's parliament gives Putin the upper hand in the crisis over Ukraine, but risks antagonizing pro-Western leaders in Kiev who have refused to resort to military action or fan tensions in Ukraine's Russian-speaking south and east.
“We are at a very dangerous point, and it threatens to push a political crisis in the direction of a military situation,” said former Kremlin spin doctor Gleb Pavlovsky.
Ukraine's leaders had no doubt who was behind the latest moves in Crimea, including a call for a referendum to decide if the Ukrainian Black Sea peninsula, which has an ethnic Russian majority, should return to its former Soviet master.
“It is not a referendum, it is a farce, a fake and a crime against the state which is organized by the Russian Federation's military,” Ukraine's acting president, Oleksander Turchinov, said in the country's capital Kiev.
Putin has in effect thrown back in Western diplomats' faces their argument that the ouster of Moscow-backed Viktor Yanukovich as Ukraine's president on Feb. 22 must be accepted because his removal was the will of the people.
Now they will have to accept the will of the Crimean people.
Former KGB spy Putin looked serene as he chaired a meeting of his most senior officials in the Security Council on Thursday, seemingly oblivious to turmoil on Russian markets and Kiev's insistence that a referendum on Crimea's status would be illegal.
The 61-year-old appears to feel he holds all the cards.
After appealing for membership of the Russian Federation, Crimea's pro-Russian leaders, installed after Russian-speaking armed men took over the local parliament, said they would have to wait for Putin's answer to hold a referendum on status.
They plan to hold the referendum on March 16, asking Crimea's just over 2 million people whether they want to unite with Russia or stay with Ukraine.
Moscow's move to get a tighter grip on Crimea has been perfectly choreographed over the last few days.
Calls to help Russian-speaking citizens in Ukraine's southeast defend themselves against “extremists” from western Ukraine, accused of trying to rid the country of Russians, have given way to draft laws speeding up citizenship requests from native Russian speakers.
Twinned with legislation to simplify the procedure for “parts of foreign states” to join the Russian Federation, this leaves Moscow better positioned to take control of a strip of land Soviet leader Nikita Khrushchev handed to Kiev in 1954.
“Now Putin is trying to assure that the situation remains under control, that someone has a grip on the situation there. But it is a very complicated situation - because from his point of view, whether he sends troops or does not send troops now - each decision will be seen by one group or another as a bad one,” a Russian security source said.
“No, he does not want a war. He is perfectly well aware of all the problems and all the repercussions of such a decision. But if the situation gets worse and worse - where else to go? Use of military force will be considered only and if all else fails, but it is an option that is on the table.”
Many Russian analysts doubt that Putin wants to annex Crimea, though Russia's Black Sea Fleet has a base there.
But they say he may consider the threat of doing so a “symmetrical response” to what he sees as Western support for armed men he says have been directing events in Kiev.
It asserts his authority once more and keeps alive his dream of creating an economic union to reunite at least part of the Soviet Union and recoup what Putin calls the lost potential of the region when the Soviet empire collapsed 20 years ago.
With only Kazakhstan and Belarus signed up so far for a Russia-led customs union, the loss of Ukraine could kill the idea. But it is a risky strategy.
Washington responded by saying it would slap visa bans on both Russian and Ukrainian officials responsible for undermining democratic institutions in Ukraine. The Pentagon also announced a large-scale air force exercise in Poland, which Washington's ambassador to Warsaw said had been augmented to reassure U.S. allies in the region in the light of the Ukraine crisis.
Russia's markets tumbled, putting pressure on a fragile economy where rouble weakness has made many Russians feel the pinch when buying imported food and clothes. Moody's said the stand-off was negative for Russia's sovereign creditworthiness.
The gap in understanding between East and West over what happened in Ukraine is, if anything, getting wider.
Foreign Minister Sergei Lavrov left talks with foreign ministers from the United States, France, Germany and Britain on Wednesday, saying their attempts to get institutions like the Organization for Security and Cooperation in Europe and the NATO military alliance involved were not building trust.