The U.S. strategy had called for a more deliberate strategy of probing special operations and infantry attacks, but intelligence suggesting that Saddam Hussein's regime was collapsing spurred the war chiefs to launch larger, faster attacks using tanks and probing deep into the city, according to The New York Times.
Those intelligence reports were reinforced Wednesday by scenes of Iraqis cheering U.S. troops in the city's streets, amid little sign of police or other security officials. Iraq's information minister, whose daily briefings have become a fixture, was also not seen.
The strategy based on that intelligence appeared to be paying off. There was no sign of any organized resistance to the U.S. advance that captured palaces, took a military airport and crossed the Tigris with tanks on Tuesday.
But the risks of that strategy have also become clear, as the Washington Post reported. There are mounting civilian casualties, so many that hospitals have stopped counting. Aid is being held outside the city because it is too dangerous to truck it in.
Tuesday saw the deaths of three journalists, two of who died when a U.S. tank fired a shell into a hotel used by many media organizations. The Pentagon said it regretted the deaths, and reiterated warnings to reporters that a war zone was a dangerous place — particularly when the zone covers a dense urban area like the Iraqi capital.
The fog of urban war could be made more cloudy by the sheer breadth of the American attack. According to the Times, the Army's 3rd Infantry Division is attacking Baghdad from three directions. The Second Brigade is fighting from the center of town, the Third Brigade is in the north and heading south, and the First Brigade is sweeping in from a different direction. Marines are attacking westward. Special operations forces are active around the city.
U.S. officials have warned that while Baghdad appears to be teetering, it might not "fall" for some time.
"This isn''t over," a senior officer told CBS News National Security Correspondent David Martin
And even when Baghdad falls, the fight may not be done.
CBS News military analysts say coalition forces are likely to move north to battles in Tikrit, Kurkuk, and finally Mosul.
Tikrit — 100 miles north of Baghdad — is the birthplace of Saddam, and continues to be a stronghold of elements of his regime.
The U.S. Tuesday began airlifting tanks to northern Iraq, where until now American troops have not had the kind of armored force that would be needed to make a move on Saddam's hometown.
As the ground war speeds along, the United States has declared air supremacy over all of Iraq, asserting its warplanes can fly anywhere with impunity, even though an Air Force attack plane was shot down near Baghdad.
Until Tuesday, the Pentagon had said it owned the skies over all of Iraq except in the Baghdad area and over Tikrit. But Maj. Gen. Stanley McChrystal, vice director of the Pentagon's Joint Staff, told a news conference that now the entire country was covered.
"Coalition air forces have established air supremacy over the entire country, which means the enemy is incapable of effective interference with coalition air operations," he said.
He did not mention that an Air Force A-10 warplane was shot down near Baghdad on Tuesday. It is believed to be the first allied aircraft other than a helicopter to be downed by an Iraqi surface-to-air missile since the war began March 20. U.S. Central Command officials said the pilot ejected safely, was recovered by allied ground forces and was in good condition.
Iraq began the war with formidable air defenses in the Baghdad and Tikrit areas, which had not been damaged by years of American and British airstrikes in "no-fly" zones over northern and southern Iraq. Iraq's offensive air forces are weak, and not a single Iraqi aircraft has taken off to challenge allied planes.
McChrystal said allied aircraft are focusing on supporting American ground forces in and around Baghdad, attacking remnants of Iraq's Republican Guard and striking "time-sensitive" targets like the Baghdad building where U.S. intelligence believed a meeting was under way involving Saddam and at least one son.