I would say both have changed. The economics has changed because, even leaving out political factors, the benefit of invading a country has greatly decreased, because the kind of war you need to wage to invade a country now will destroy whatever wealth in that country you were hoping to gain by invading it. And the political factors have changed because previous ways of trying to reduce the cost of controlling a country will now trigger consequences (in the form of actions by other countries) that they didn't before.