Look at a map of Europe, put yourself in the mind of a highly suspicious and pessimistic person and ask yourself "how would I invade Russia?" "how do I get an SRBM or MRBM within striking range of Moscow?" "how do I increase my ability to have Russian speaking agents plausibly cross into and out of Russia?"
Now put yourself in the mind of someone else seeking power and look at the map and, keeping an eye to history, ask yourself "what is the most effective way to destabilize Russia without involving US forces?"
Both parties are playing a very dangerous game that has a non-zero chance of ending with a nuclear exchange, limited or not. If peace was the goal then both sides need to agree to an immediate ceasefire and withdrawal of both military and political forces. A new agreement needs to be reached that places Ukraine as a neutral, sovereign country and both sides should pay for reconstruction efforts and restitution to survivors. Of course, peace is never the goal.