Why was constant warfare the apparently inevitable consequence of the rise of the absolutist state?
Because one the state becomes basially the toy of the sovereign, it becomes a reflection of his honor, and so to enlarge one is to enlarge the other. It’s the same reason that people with sports cars drive fast even when they shouldn’t. The wars were fought also because the people who start the wars (the sovereigns) aren’t connected with the people fighting the wars (the commoners). Modern democracies, for instance, try to prevent this effect by having the leaders elected by the folks who would fight any war.