Kyiv attempts to enter Russian airspace, flying over Crimea.
NATO is surrounding Russia with military bases. The USA were planning to build a military base in Ukraine, about 300km from Moscow. Ukraine is an artificial state and the government in Kyiv should allow the people from all its parts to carry out self-determination – to secede from Ukraine and join Russia.
There is no evidence for that claim that the USA is planning to build bases in Ukraine. The separatism in both Crimea and in Donbas was sparked and greatly supported by Russia. The referendom in Crimea was considered illegitimate by the international community, as are the so-called "People's republics" in Donbas. Furthermore, a recent poll suggest that 57% of Ukrainians have negative feelings towards Russia while 43% would be positive towards joining NATO