In a Republic, I believe it comes down to the voters.
It's not the President's fault that some milquetoast voters keep voting milquetoast Senators in. And it's not the President's fault that conservatives swallow whatever negative garbage the MSM feeds them. That's the fault of ignorant voters.
For example...Taliban resurgence in Afganistan? LOL. Just what Hillary and her Paula Zahn cohorts want you to believe.
You have your head up your ass if you think that the Taliban aren't a threat to come right back in if we don't do more to gain control in the countryside. They have unhindered control of the border regions, funding from ISI, drug lords and Saudi money, and allies in several of the former warlords. The Afghan government controls Kabul. Nato has bases from which it sends out sorties now and then.
Afghanistan is by no means a country that is on a glide path to self-sustained stability. The second we leave, it is done for. Entire regions are out of our effective control, and not controlled by the central government, either. You have no idea what you are talking about.