According to NATO, Russia is looking for a “casus belli” at the moment. That is an act or event that provokes or is used to justify war. An example can be staging a “false flag operation” like a fake attack against Russian citizens in Eastern Ukraine.
On 17th February, the Ukrainian government accused the Russian separatists of bombing a kindergarten. The Luhansk separatists said that it was a response to an earlier Ukrainian attack on their territory.
Also on 17th February, the British–Polish–Ukrainian trilateral pact was launched. The London-Warsaw-Kiev axis aims to work together for European security. Ukraine has three other military alliances: Lublin Triangle (with Poland and Lithuania), Association Trio (with Georgia and Moldova) and Quadriga (with Turkey).
On Friday, the leaders of Luhansk and Donetsk separatist republics from Eastern Ukraine called for mass evacuation of the civilians.