The U.S. encountered a daylong act of defiance on Tuesday in the face of an invasion force of more than 250,000 troops ringing Iraq, a nation of more than 23 million that Saddam Hussein has ruled brutally for nearly a quarter century.
One day after President Bush set his deadline of 8 p.m. EST on Wednesday for Saddam and his sons to leave the country, troops in the Kuwaiti desert loaded their ammunition and combat gear into fighting vehicles, ready to invade on short notice.
"I think I'd probably have a better chance of being elected pope than we have of Mr. Saddam Hussein leaving the country," Capt. Thomas A. Parker said aboard the USS Kitty Hawk -- an aircraft carrier preparing to take on a supply of 1,000-pound, satellite-guided bombs from a nearby munitions ship.
"So this is probably going to follow to its logical conclusion."
In an edgy prelude to war, Saddam mocked an American ultimatum Tuesday to surrender power, and the Bush administration claimed public support from 30 nations for its international coalition supporting Iraq's disarmament.
The streets of Baghdad captured the moment -- panic buying by residents bracing for a fearsome U.S.-led attack, side by side with a government-prompted, mass demonstration in support of Saddam.
"This war, in short, is tantamount to genocide," charged Mohammed Al-Douri, Iraq's ambassador to the United Nations, in one of a string of insults the Iraqi high command hurled at Bush.
As the hours dwindled toward Bush's deadline, the White House worked to keep Saddam guessing.
Presidential spokesman Ari Fleischer would not rule out a U.S. attack before Bush's 48-hour clock ran out. "Saddam Hussein has to figure out what this means," he said.
One official, speaking on condition of anonymity, said Bush was leaving the door open in case Saddam makes a pre-emptive attack or U.S. intelligence warns that one is likely.
Underscoring what Bush said on Monday night, Fleischer said U.S. troops would enter Iraq, either as an invading force or as part of an unmolested effort to locate weapons of mass destruction.
Turkey's government, meanwhile, said it would ask parliament to grant the U.S. Air Force the right to use Turkish airspace in an Iraq war and that a separate motion allowing in U.S. troops could be considered at a later date. Last month, the Turkish parliament rebuffed a resolution to let in tens of thousands of American soldiers, opening a northern front against Iraq.
At the same time the administration prepared for an invasion, it announced a series of steps at home to protect against terrorist attacks.
"We know that our interests have been attacked abroad. And we should prepare for potential attacks, either here or abroad at this time," said Homeland Security Secretary Tom Ridge.
The plan, dubbed "Operation Liberty Shield," heightens security at the nation's borders, airports, seaports and railways, at nuclear and chemical plants, and in elements of the nation's food supply and distribution system. Ridge said governors are being asked to deploy National Guard troops or extra state police to help.
At the State Department, Secretary of State Colin Powell said 30 nations had joined the administration's "coalition of the willing," and that another 15 had quietly pledged support.
But at least two of the 30 nations, Spain and the Netherlands, have explicitly ruled out the use of troops to invade Iraq. Another, Japan, was identified as only a post-conflict member of the coalition.
State Department spokesman Richard Boucher said some of the countries "may put troops on the ground" and others may take on roles such as assisting in a defense against the use of chemical and biological weapons. Intelligence reports indicate that Saddam has given his field-level commanders the power to use chemical weapons, without instruction from the leadership, Pentagon officials said Tuesday.
With war looming in the Persian Gulf, the diplomatic and political fallout circled the globe.
In London, the House of Commons backed British Prime Minister Tony Blair's strong endorsement of Bush's policy, defeating an anti-war resolution and then voting in favor of using "all means necessary" to disarm Saddam. Blair has suffered in public opinion over his support of Bush, a stance that led three ministers to resign from his government this week in protest.
French President Jacques Chirac, whose country led opposition to war within the U.N. Security Council, said Bush's action would undermine future efforts at peaceful disarmament. "Iraq does not represent today an immediate threat that would justify an immediate war," he said.
German Chancellor Gerhard Schroeder concurred, and said U.N. weapons inspectors should have more time to try to disarm Iraq of weapons of mass destruction.
Both European leaders were sending their foreign ministers to a Security Council meeting set for Wednesday in New York.
But by Bush's word, laid down in a stern speech Monday night, the time for diplomacy -- and weapons inspections -- had clearly come and gone.
Arab League Secretary-General Amr Moussa scrapped plans for a last-minute peacemaking trip to Iraq. And the U.N. peacekeepers boarded a plane out of Iraq, their mission at an end.
For his part, the Iraqi leader appeared on television wearing a military uniform for the first time since the Persian Gulf War in 1991.
Iraq's al-Shabab television, owned by one of Saddam's sons, said the decision to defy Bush's ultimatum was made in a leadership meeting chaired by the Iraqi leader.
"The pathetic Bush was hoping ... to achieve his evil targets without a fight," it said. "... The march of struggle will continue against the American, English and Zionist aggressors."
The Associated Press contributed to this report.