Iran, doubtful as he seems to be doing the same kind of tactic that go him closer with North Korea.

Even if it did come to war with Iran, we have already seen that they cant do shit to our aircraft (via proxy by the Israelis), and all we would have to do is destroy the key targets and let the massive anti-Regime sentiment we always see bubbling below the surface make Iran Persia again. All without us having to put a single boot on the ground (other than the usual "get in, get out" Operator-shit types).