That's a good point. It may simultaneously be true that globalism doesn't prevent irrational war to the degree that we had hoped, but it does still prevent it more than some other economic alternative.

(Personally, I think the best way to prevent war is non-corrupt democracies with little autocratic power concentration and a strong fair press. Most people don't want to go to war and kill others, so when you give the entire populace agency over what the military does, you get a lot less irrational wars.)