As a nation, we are like alcoholics who have not yet recognized our addiction to blood, as we have to oil and freedom. Add to the mix our religion—also born in blood (of a gentle, homeless, apolitical Hebrew rabbi, prophet and martyr 1,980 years ago and 9100 miles away)-- as we must to sell a war to the American people, whereupon we’re capable of just about any atrocity. When there is no popular jihad to harness the dark energy of our addiction, nor a plan for transmuting it, we turn it on ourselves in homicidal and suicidal frenzies.
Perhaps, most likely, the flaw lies in the Homo Sapien species itself. So that any other nation that might supersede us would do no better at fomenting peace; although it would be interesting to see if the Swiss could do better. Assuming it unlikely we would turn things over to the Swiss or that they would accept it, our best prospect for a future that dodges Armageddon ---for western civilization, at least-- would be the wholesale evolution of our species toward what some scientists are calling Homo Evolutis, via emerging technologies such as genetic manipulation, robotics, and the ancient technique of wealth redistribution. You can bone up on Homo Evolutis here:
Meanwhile, Randy Newman captured this capricious, subconscious bloodlust and death wish in our collective DNA perfectly, ironically, in 1973, updated here a bit in 2004 and well worth listening to today.