WASHINGTON (AP) -- A series of secret U.S. war games in 1999 showed that an invasion and post-war administration of Iraq would require 400,000 troops, nearly three times the number there now.
And even then, the games showed, the country still had a chance of dissolving into chaos.
In the simulation, called Desert Crossing, 70 military, diplomatic and intelligence participants concluded the high troop levels would be needed to keep order, seal borders and take care of other security needs.
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"Iran's anti-Americanism could be enflamed by a U.S.-led intervention in Iraq," the briefings read. "The influx of U.S. and other western forces into Iraq would exacerbate worries in Tehran, as would the installation of a pro-western government in Baghdad."
http://www.cnn.com/2006/WORLD/meast/11/04/war.games.ap/index.html