By giving lethal assistance to the Ukrainians, he is perpetuating the frozen conflict in the Donbass by balancing the defensive capabilities of the Ukrainian forces against the offensive capability of the Russian separatist forces (and vice versa), thus ensuring that Ukraine cannot unite in the foreseeable future by force, which favors Russia keeping a destabilized Ukraine out of the EU and NATO, achieving Putin's strategic regional aims.
Therefore, collusion! IMPEACH! RESIST! NON SEQUITUR!