[nl]

countries that are under the umbrella of the United States and have highly developed economies don't go to war against each other

Except in the case of the Falklands War. And the Israeli bombing of the Iraqi nuclear reactor (Iraq was a US ally at the time). And the Turkish/Greek air battles over the Aegean Sea (eg, Turkish & Greek F-16's dogfighting and crashing into each other in 2006: http://en.wikipedia.org/wiki/Greek%E2%80%93Turkish_relations...).

I agree with your general principle though.