Look we want all countries not to have WMD (even including the US). So this is part of our normal diplomatic negoiations- we are trying to get to this condition working on a series of agreements with different govts.
It is different in the case with Iraq- that country sued for peace and part of that agreement was regarding WMD. Instead of asking for WMD (or in addition), we could have [for instance] negotiated for changing the border (move it 50 miles north of Kuwait's current border) or many other things. War is the "normal way" of *making/creating* countries, wars are fought and borders can change as a result of the war. That's why if you look at old maps, there are different countries and borders are in different locations, that's also one reason why you have conflicts- some people don't accept the result of some war, whether it's borders, who is running the place, or even some particular law. It's also why we aren't a colony of the British empire.