NATO in fact gave impression to Ukraine to be its ally. Though this promise was not kept it resulted in Russia imposing massive security pressure which led to the current situation in Ukraine. Total noncommitment and provocation from the part of NATO only worsened the situation. Russia should have avoided war with Ukraine and not escalate the already worsening situation. European countries too have failed to either resolve the issue diplomatically or by putting pressure on Russia. Even the European powers failed to interfere and establish peace through proper channels. Ironically, it may seem that Ukraine was cheated by the international community. If they had nuclear weapons, would they have been so blatantly attacked by Russia. I doubt if Russia would have gone ahead with war with a nuclear powered Ukraine.
http://The Ukraine-Russia conflict apparently made Trump forget about his horrific role in NATO (msn.com)
Trump was trying to build an American-Russian alliance. However, Putin is wanting to restore the old Soviet sphere of influence at the same time. Anyway, of course, some smaller old Warsaw Pact nations will object - because many in those nations resented former Soviet rule.