If other countries come to view such promises as worthless, and the US a weak, worthless ally, which is indeed happening, then there WILL be at least a medium scale nuclear war in the not too distant future. I give it 10 - 50 years, and better than even odds that the US will not be directly attacked. But... the radiation will kill millions of US citizens and the world economy will collapse. The movements toward that war are already underway (but not unstoppable with strong leadership by the US.)
You hear people say the US should not be the world’s “cop”. They never discuss or understand where that leads.
I will not deny that there has been a rather drastic shift away from global peace and stability and towards anarchy, war, and atrocities in the last 6 years of the Obama policy.
I also do not deny the essences of the Obama policy being mostly what I described as being the primary cause.
I would still however insist upon the former treaty process, not the mere word of Presidents and the prepetulay corrupt State department’s words/’assurances’. It is not wise to invest such power and reliability in such corruptible offices.
So you see it is not that we shouldn’t encourage stability and defend allies, its that we MUST do it thou the constitutional process if it is to be respected as binding. Otherwise people like Obama will be using that same word to push his social agenda around the world.
I would however point out that Russia would not have taken Crimea if the Ukraine had such an alliance with anther nuclear power. The Ukraine should have insisted upon a treaty which presumably means giving up something more valuable to us than just their nuclear weapons.