A direct threat against the US no, against our allies yes. Namely Israel. A direct threat to other smaller countries yep. Ever been to Kuwait? Still can see the carnage from what the Iraqis did there.
A treaty is a treaty, rules are rules either enforce it or dont have it. Break the rules suffer the penalties.
Focus away from Afghanistan? Well whatever you think. They are both in the same region half a days flight apart.
Ummm yes common sense the more you spread your resources the less you have to commit to other areas.
Again your opinion to which you are entitled to.