On the one to Ukraine, we promised to provide protection to a WHOLE neutral Ukraine on condition they give up nukes, not just one part of a divided Ukraine. (Eastern Ukraine contributed to this denuclearization too). If Ukraine is divided, we have no moral ground to protect one part of this country against the other part. But we stupidly helped to divide this country on 2014 with a coup that overthrow a president elected under UN observation and favored by eastern part of Ukraine. We helped to divide this young country by ignoring her long complicated history and did it without realizing how dangerous it is
On the promise to Russia, we promised NATO wouldn't expand one inch beyond eastern Germany in exchange for Russia to agree we keep military at Germany after Russia military leave Eastern Germany. We broke this promise by allowing many countries to join NATO. Ukraine is the one that is Russia bottom line. All Russia wants is our promise that doesn't allow Ukraine to be in NATO. We didn't. We lost our moral ground to act on both Ukraine and Russia.