Iraq's leaders put their nation on high alert for terror attacks over the weekend, preparing for the possibility of a spike in insurgent attacks as the U.S. military formally ends its combat mission. Iraqi security forces have been hammered with bomb attacks in the days since the final American combat troops left, prompting criticism that the Iraqi government isn't prepared to protect its people without U.S. help. President Obama, who will make an address about Iraq on Tuesday, says the U.S. will press on with its withdrawal plans regardless. But, realistically, how long will the U.S. have to maintain a significant military and civilian presence in Iraq? (Watch Obama's salute to the troops)

The U.S. military needs to stay several more years: If we pull out too abruptly the country could go "spiraling back into civil war," says Irena L. Sargsyan in the Los Angeles Times. We still have 50,000 soldiers who are scheduled to stay in Iraq until the end of 2011 — but realistically, if we want Iraq to have a shot at stability we'll have to stick around a few years longer than that.
"Winding down the Iraq war, and avoiding civil war"

Try several more decades: It's good that we're pushing the Iraqi government to start standing on its own two feet, says Noah Feldman in The Wall Street Journal. But let's look at a comparable case: The Korean War ended nearly 60 years ago, and we still have 30,000 troops in South Korea. If we truly want to give democracy a chance to take hold in Iraq, we'll be staying there for decades.
"A very long engagement"

It's time to leave, now: There are "more than 100,000 U.S. troops and mercenaries... continuing to engage in combat and continuing to die" in Iraq, says Kevin Zeese at Huffington Post. That's not building stability — it's just extending a tragic blunder. Obama should honor the spirit of his pledge to end the Iraq war by bringing "home all the troops and handing over all military bases" — and doing so immediately.
"Is the Iraq war over?"