I think NATO Countries will have to declare war on Russia (in some way) before Trump is inaugurated. Why?

Because otherwise Europe's democracies will ALL cease to exist within a few years. 

They are in a sink or swim situation where unless war is declared by NATO before Trump gets into office they won't exist anymore. At that point (during a real war) Trump becomes irrelevant completely once all out war begins between NATO and Russia. Under Biden the war could be over with Russia defeated by the time Trump takes office also. This could be a nuclear war BEFORE Trump is inaugurated or it could be just missiles hitting Moscow and Washington DC and all the Capitols of Europe. It's hard to say how this is going to go presently.