That's true, but ultimately what causes wars might have to do with the impulses of people as much as with the "international situation". While institutions can be put in place that seem to make war less likely, people today are not that different from people yesterday.
People almost never want war. They have to be spurred into it by a combination of heavy propaganda and desperate economic circumstances. The first is often enough if the war is one that most citizens will only see on TV, like all 'wars' America has waged since WWII (they are 'wars' in the sense bullfighting is 'fighting'.)
Real wars, on the other hand (e.g., an hypothetical Germany invading France), would require a big crisis.
Which, on the other hand, is almost guaranteed, cyclically, by the current money system, and otherwise easy to summon, by contracting the money supply.
