( CNN ) -- Crimea 's parliament has voted to secede from Ukraine and join Russia , and has scheduled a referendum for its residents to decide whether to stay or go . It is one of the biggest developments in the fast-moving crisis in Ukraine . Who is voting ? The voters deciding Crimea 's future would be the residents of that region . Crimea has a population of about 2 million . Crimea is known as a pro-Russian area , but it is not without its diversity . The autonomous region has a 60 % ethnic Russian population , having been part of Russia until it was ceded to Ukraine in 1954 by the Soviet Union . But not everyone may be as keen on coming under Moscow 's direct influence . A quarter of the peninsula 's population is Ukrainian and about 12 % Crimean Tatars , a predominantly Muslim group . The Tatars have shown no interest in breaking away . How much credibility will the vote have ? The legality of the referendum has been challenged from the outset . While the Crimean parliament voted to hold the referendum , at the federal level , Ukrainian leaders say a referendum is illegal . It 's an `` illegitimate decision , '' interim Ukrainian Prime Minister Arseniy Yatsenyuk said Thursday . `` Crimea was , is , and will be an integral part of Ukraine . '' Justice Minister Pavlo Petrenko said the Crimean parliament 's decision is illegal because under the constitution , only national referendums are permitted . The Organization for Security and Co-operation in Europe has sent a military observer mission to Ukraine , but it can only expand its mission to monitor the vote if the Ukrainian government invites it to . In Crimea , worlds collide . What 's next if the referendum passes ? See above . Even if the vote goes as planned , its legitimacy will continue to be questioned . Michael Crawford , a former British ambassador in Eastern Europe , cautioned that whatever the result of the vote , it may be meaningless . `` It does not follow that if Crimea votes to join Russia , that anyone will accept it , '' he said . `` For Russia to start cherry-picking bits of the former Soviet Union , cranking up referenda in Kazakhstan or Latvia or wherever you like , to try to carve off bits , would be against international law , and it would be something ( that Russian President ) Vladimir Putin has said he does n't want to do . '' In short , it is not clear how easily Crimea could secede from Ukraine and join Russia . Who would benefit from Crimea 's secession ? It is not clear . At first glance , it may appear that many Crimeans would get what they want and Russia would gain a territory , but the benefits are not so clear-cut . `` While separatism may seem emotionally gratifying to some ( Crimean ) residents , the practical results seen elsewhere , especially in South Ossetia and Abkhazia , have been economic isolation and a heightened dependence on Russia , '' Michael Hikari Cecire , an expert on the region , wrote recently . South Ossetia and Abkhazia are two separatist regions of Georgia that Russia occupied in 2008 . For Russia , peeling off a slice of territory from Ukraine is n't productive , Cecire wrote . Its goal is to get all of Ukraine under its influence . Taking steps toward separatism has only deepened the crisis , as Russian intervention has galvanized anti-Russian sentiment in other parts of Ukraine . The referendum , scheduled for March 16 , will probably just add fuel to the fire . Five possible directions in Ukraine .
Crimea is 60 % Russian . The Crimean referendum may be illegitimate , experts say . But the people of Ukraine are not going to let Russia take over their country