The table comes from a discussion of “Democratic Peace Theory” that basically says that democracies do not fight one another; however, democracies tend to fight non-democracies at about the same frequency as non-democracies fight whoever.
Democratic Peace Theory is more of a possible solution to interstate war than a cause.
I think this was part of the rational for Gulf War II, in that there was a hope of instilling democracy into the Middle East. Unfortunately, that did not work out so well.
Also, Hitler was elected so democracies can change. I don’t know the history of the Roman Empire well; however, wasn’t Rome a democracy before the first emperor?
Anyway, Democratic Peace Theory does get a lot of attention.
Unfortunately, the two main adversaries of the U.S. mentioned by the OP are not democracies.
Thus, the actual cause of interstate war, as well as the cure /solution remain unknown.
As a believer, I believe that part of the answer is in evangelization since I don’t think we can promote peace without God’s help.
