The world does not recognize the annexation of Crimea. Only Russians think so. Also peoples have the right to self-determination but only a part of the country on whose territory they reside. You forgot the reaction of Russia to self-determination of the Chechen Republic?
Before the disintegration of the USSR, around one-third of the population of Chechenya was Christian and white. These people lived in the districts of Shelkovskoy and Naursky. These two districts were actually Terek Cossack homeland, but gifted to Chechenya by the Soviets (just like they gifted Crimea to Ukraine). Also, the lowland Chechens were pro-Russia and they never supported the independence movement. Less than one-third of the Chechens wanted to secede from Russia. In Crimea, more than 90% of the population wanted to be part of Russia.