Politics in general are weird. Most of it is just a show by now. In theory, but only in theory, a politician's job is supposed to be one of very high importance and with very high responsibility. They're supposed to be representatives of the people, of us, of our interests. In reality however, even though a few individuals might still believe it and a few might want to have a positive impact on the world, there isn't much they can actually do. Once they get into a position of power, a leash is put on. Politicians will only do what the other "
players" allow them to do. If it is in these other players' interests to take a president down, they will. If what he's trying to do is actually serving them aswell, they'll let him do it. The reason why nothing has been done against him yet is either 1. because his actions serve their interests aswell, or at least to some degree, and they want to see how it will play out or 2. because they directly tell him to do these things, it's part of the plan. They only allow this nonsense with North Korea, because they'll gain something from it. They don't do the same with Iran, because they have other plans for them, probably another war down the road or something.
Once they have no use for the president anymore or he becomes a threat to them they'll dig something out and force him to resign. If he refuses, they might do worse things to him.
Politics being the show it is also means that they're a distraction from the deeper, core issues we have in our society. Stir the shit up, make it even more chaotic, that way nothing really changes. They succeed even more by keeping people uneducated or, if they can, getting actually support from them in one way or another. If you can get people angry at minority-issues, or something of less significance on a global scale, good enough! If you can get people to not care about the world and what's going on and care more about smartphones, cars, etc., well done, one more enemy less! If you can actually corrupt people and add even more chaos, even better! So far they're winning the game.