America is the WORST international ally to get involved with. America will betray and abandon any and all allies just on some stupid whim. There are decades of examples to prove what I am saying.
Not only is America an unreliable ally, America is actually a dangerous ally to have in time of war. They are dangerous in that American foreign policy makes a promise written in stone, and American politicians parrot foreign policy declarations, but when war breaks out America can easily change immediately for any reason.
Depending on America is dangerous, and can get you slaughtered. Just ask all of the Vietnamese, Afghani locals, Iraqi locals, and Hamas hostages, who believed America would never abandon them. America is a childishly fickle military ally when any kind of trouble arises.