The thing which can prevent "the ugly sisters" (religion, nationalism, ideology) to completely take over peoples' minds is a good broad education. Not that there couldn't be a well educated "monster" but in majority people become wiser when learned and are less liked to get their minds scrambled. Even more important is the possibility of free interaction with people of many different opinions and sets of mind. Then its obvious that other people, not sharing imposed on you worldview, are quite normal, kind, happy, not some strange evil creatures as may be pictured by "ugly sisters'"propaganda.
Of course a radical communist, a racist or a religious fanatic could look nice, clever and kind on the surface too. But I think after a wile and after some "digging" the difference between a free thinker and an affected person will be obvious to anybody. There are millions of people in the world mildly affected by one or all three of "ugly sisters". They are OK. For the moment. But I have a feeling there is always a possibility of them moving towards a fanatical end.
I'm not normally in favor of military intervention by any country unless its absolutely necessary to prevent a genocide. I think if anybody want to help people living under tyranny, cruel law and with closed minds they should help to educate them, to broaden their minds. Invite lots of them into your universities, broadcast to them, send your teachers to them. And then the bloodshed may not be needed at all.