"They're ready to go right now," as soon they get the call from the commander in chief, says CBS News Military Consultant Gen. Joe Ralston, USAF ret.
While a few more days might allow slightly better preparedness for U.S. troops, the risks of waiting outweigh the advantages, Ralston says.
"If we had a few more days or hours you might get from the 96th percentile to the 97th" of readiness. "But if you wait for that you might get some unknowns that the other side might do."
Those unknowns include the grim possibility of a pre-emptive Iraqi attack with chemical weapons. But, Ralston says, "If we thought they were going to launch a chemical attack we'd come down on them like ton of bricks."
With President Bush promising swift military action once the Wednesday deadline passes, Ralston says, "the element of surprise is gone" for the U.S. military in a strategic or tactical sense. But the real surprise for the Iraqis "is how intense the reality" of the initial U.S. aerial assault will be.
The U.S. will launch a "horrendous air campaign" led by cruise missiles and Tomahawks aimed at taking out Iraq's heavy air defenses. Naval and Air Force aviators will follow.
"It's going to be hell of a lot worse than the Iraqis thought," Ralston says.
The president, in his Monday night address, urged Iraqi soldiers not to give up their lives for Saddam Hussein, and U.S. military planners are counting on the "shock and awe" of the massive air assault to convince many of them to surrender.
Ralston says the regular Iraqi army of some 300,000 troops "is deficient in just about every measure - equipment, training and loyalty" to Iraqi leaders.
"The regime cannot count on the regular army," he says.
A likely scenario is that large numbers of Iraqi soldiers will give up after the air campaign – which should last less than a week – clearing the way for Gen. Tommy Franks, the top U.S. military commander, to order the ground invasion.
Of more concern to U.S. war planners is the Republican Guard, Saddam's best fighting unit. CBS News National Security Correspondent David Martin reports five of the six Republican Guard divisions have now left their garrisons and dispersed throughout the country in what appears to be an effort to ride out the initial attack.
The Republican Guard, Ralston says, "is a big step up" from the regular army. "But how loyal they are is unknown."
Meanwhile, the waiting continues. And for the thousands of U.S. troops on high alert in the Persian Gulf, the waiting can be tough.
Ralston says the challenge for their commanders is to keep them ready and "have them peak at the right time."
By Joel Roberts