In my opinion, there is little NATO can do for Ukraine in the military field. Certainly, will not intervene militarily on the side of Ukraine, because Ukraine is a non-member state and Russian Federation is still a nuclear power. This would cost too much and simply does not justify such a move, because the strategic gain of the intervention will be minimal. I think that the only thing NATO can do in this crisis is to give military assistance for the Baltic states, Poland and Romania, in a way that would affect Moscow and would discourage any violent Russian attempt to move forward in its control over Ukraine.
I think that there are some red lines about which every part in this conflict knows, and tries to see what will happen if they make a small step and cross one of them. One example is the Russian military takeover of the peninsula of Crimea, where the military troops which invaded it didn’ t wear any signs to give information about their origin. This is an example of how they test the ground and see how further they can go. This is also available for NATO. It needs to move military equipment in the region, on the territory of its member states in order to discourage Russian military moves. It is indeed a chess game, but without capturing the opponents pieces, because this would mean war.