Wrong-o. You can post US soldiers on every damn street corner, and it will only do 2 things:
/1/ Provide more American targets for snipers and bombers, and
/2/ Postpone ("enable") the day that the Iraqis are forced to step up to the plate and deal with the terrorists and provide their own security.
500,000 troops in Iraq would be a monumental blunder, as it was in Viet Nam, when the conventional-minded ground-pounder generals decided that the Special Forces and counterinsurgency troops weren't "winning the war fast enough."
You want to see a real quagmire, send in 500,000 troops.
That's what the red anti-US sovereignity types wanted to see- they hope for it. They must really have been disappointed when we didn't send the whole freakin US Army into Afghanistan, Russian-style. And then that speedy invasion of Iraq- we were supposed to be bogged down in a seige war south of Baghdad, where they and the world press could have more time to fire up their dreamed-of mass protests with draft-shocked youngsters like they did in Vietnam.
Your opinions are noted, respected, and appreciated.