I’ve got a monster essay up at AskTheHarvardMBA.com:
http://www.asktheharvardmba.com/2008/05/03/is-global-economics-a-zero-sum-game/
In it, I explain why global economics is not a zero-sum game, how cavemen can illustrate both the power of innovation and comparative advantage, and how competition from Japanese automakers is a huge net positive for America (though they did cause some collateral damage–to wit, the career of Michael Moore).
Check it out!
http://www.asktheharvardmba.com/2008/05/03/is-global-economics-a-zero-sum-game/