Bush said he understands how Americans might lose patience with a war that has lasted longer than the U.S involvement in World War II. Polls show popular support for the war has fallen to its lowest levels ever.
But Bush urged patience. "It can be tempting to look at the challenges in Iraq and conclude our best option is to pack up and go home," he said. "That may be satisfying in the short run, but I believe the consequences for American security would be devastating."
In an eight-minute televised statement delivered at the White House, Bush acknowledged that the effort to pacify Iraq sometimes has "bad days." But he noted that, thanks to the war, Iraqis no longer have to live under Saddam Hussein, and now have a constitution as well as a democratically elected government.Most Important Mission Of War
And while Bush conceded that more needs to be accomplished by Iraq's leaders to meet the goals of a stable society, he briefly outlined the consequences of a U.S. troop withdrawal before the job is done in Iraq
"If American forces were to step back from Baghdad before it is more secure, a contagion of violence could spill out across the entire country," he said. "In time, this violence could engulf the region. The terrorists could emerge from the chaos with a safe haven in Iraq to replace the one they had in Afghanistan, which they used to plan the attacks of September 11, 2001."
Bush said it's too early to determine the success of his new strategy of sending an additional 21,500 troops to Iraq. Most of the troops are to help quell the sectarian violence in Baghdad, which he called the most important mission of the war.
The president said Iraqi Prime Minister Nuri al-Maliki and General David Petraeus, the U.S. commander in Iraq, told him this morning that the strategy will take months, not weeks. But he said reports from Baghdad are that the strategy already is showing signs of success.Congressional 'Responsibility'
Bush also urged Congress to act quickly on a bill that would provide more than $95 billion to continue funding the wars in Iraq and Afghanistan. And he said it must have no conditions
"Members of Congress are now considering an emergency war-spending bill. They have a responsibility to ensure that this bill provides the funds and the flexibility that our troops need to accomplish their mission," Bush said.
"They have a responsibility to pass a clean bill that does not use funding for our troops as leverage to get special-interest spending for their districts," he continued. "And they have a responsibility to get this bill to my desk without strings and without delay."
Some members of the opposition Democratic Party, which now controls both houses of Congress, plan to add as a condition to the funding a requirement that all U.S. forces be withdrawn from Iraq by no later than September 1, 2008.
Bush's statement came a day after demonstrators around the country also marked the fourth anniversary of the start of the war.
In Washington, thousands of war protesters marched to the Pentagon. This was countered by a demonstration of those supporting the current U.S. policy in Iraq. The two groups exchanged angry shouts, but no serious trouble was reported.
There also were demonstrations in other U.S. cities on March 18, including Los Angeles, San Francisco and San Diego in California, and Hartford, Connecticut.
THE COMPLETE STORY:
RFE/RL's complete coverage of events in Iraq and that country's ongoing transition.