A Presidential signature on a document isn' t worth squat. Everyone in the world knows that.
Without Senate Ratification of a Treaty the USA did not commit to anything concerning Ukraine.
Asw for the majority of the Ukrainian people, they voted for a pro-Russian president in a free and open election.
As for NATO? We need to STOP it's expansion, and now. NOBODY in the US wants to go to war to defend Ukraine or Georgia.
Yeah, we have to honor our commitment to the Baltics, Romania and Bulgaria (really, Bulgaria?), but we needn't make such folly worse.
Sigh. If that is the thought process, then indeed we are a worthless people, and deserve what we will reap. If a formal agreement reaffirmed by multiple Presidents is meaningless, then Treaties are not far behind. After all, if a Treaty has become unpopular within the U.S., who the heck is going to make us honor it? Estonia? The U.N.?
Honorable people, and countries, honor their obligations even when it may not appear to be in their short term interest. I’d try to explain again why that is important, but it seems to be beyond many. :-(
That doesn’t mean we have to send troops to Crimea. We could just return the value to Ukraine of those 5000 nukes they gave up in return for our promise of protection.
The “folly” you speak of has kept the peace for many years, for the most part, in (historically) a particularly warlike and brutal part of the world. Russia never liked it, and if they don’t like it now, that’s an argument to bolster NATO further, given Russia’s return to their historic ways.