With a signature, US war in Iraq is over

There was no ceremony this time, only Defense Secretary Leon Panetta and a piece of paper.

Just before 7 a.m. Sunday, Panetta signed the official order that ended the nearly decade-old -- and highly controversial -- Iraq war.

"At 6:59 A.M., Secretary Panetta approved the order officially ending the Iraq war," Pentagon press secretary George Little tweeted shortly after.

The order is called "EXORD 1003 Victor, Mod 9," Little noted.

The last American troops have left Iraq, meaning for the first time since early 2003 no U.S. soldiers or Marines are conducting patrols, storming suspected insurgent safe houses or hunting for improvised bombs.

The White House puts the cost of the conflict at nearly $1 trillion, and the Congressional Research Service puts the tab at nearly $900 billion.

Over 4,500 U.S. troops died, and over 30,000 were wounded.

Many regional experts say it is too soon to know whether the operation was a strategic success or blunder for Washington.

The experts say that is up to Iraqi officials' ability to keep in place a government that is representative of its three main sects, while also fashioning an oil revenue-sharing pact and fighting Iranian meddling in their affairs.