WASHINGTON – Faced with persistent concerns about progress in Iraq, President Bush yesterday pointed to successes there, such as last week’s elections, defended his decision to invade the country despite difficulties securing it, and reached out to critics of the war with a plea for patience.

In a prime-time speech from the Oval Office, Mr. Bush said that while certain aspects of the war have not gone as planned, others are cause for optimism. His speech came on the same day that Vice President Cheney made a surprise 10-hour visit to American troops in Iraq, and terrorists killed two dozen across the country.

“Defeatism may have its partisan uses, but it is not justified by the facts,” Mr. Bush said. “For every scene of destruction in Iraq, there are more scenes of rebuilding and hope. For every life lost, there are countless more lives reclaimed. And for every terrorist working to stop freedom in Iraq, there are many more Iraqis and Americans who are working to defeat them. My fellow citizens: Not only can we win the war in Iraq – we are winning the war in Iraq.”

Last night’s speech was the fifth time in three weeks that Mr. Bush has spoken formally about the war, and it marked the culmination of a weeks-long effort by Republicans to take back control of the debate over Iraq. Democrats had the upper hand briefly last month when a hawkish Democrat, Rep. John Murtha of Pennsylvania, called for a withdrawal of American troops within six months. The same week, Republicans asked Mr. Bush to provide Congress with quarterly updates on the war.

Last night, Mr. Bush delivered an update in which he mixed the acceptance of blame with poignant accounts of why he regards the war as “a difficult, noble, and necessary cause.” Mr. Bush conceded, as he has at other times in recent weeks, that the decision to invade Iraq was driven, in large part, by false intelligence about Saddam Hussein’s weapons capabilities.

“It is true that many nations believed that Saddam had weapons of mass destruction,” Mr. Bush said. “But much of the intelligence turned out to be wrong. And, as your president, I am responsible for the decision to go into Iraq.”

At one point in the speech, Mr. Bush cited visits with injured soldiers for his determination in the face of obstacles in Iraq. He called such visits a reminder of the “tough decisions” he has had to make regarding the war.

“I see the consequences of those decisions when I meet wounded servicemen and women who cannot leave their hospital beds, but summon the strength to look me in the eye and say they would do it all over again,” Mr. Bush said. “I see the consequences when I talk to parents who miss a child so much, but tell me he loved being a soldier, he believed in his mission, and, ‘Mr. President, finish the job.'”

Mr. Bush also cited stories about Iraqis who are proud of the Democratic reforms there as bolstering his resolve.

“One Iraqi, after dipping his finger in the purple ink as he cast his ballot, stuck his finger in the air and said: ‘This is a thorn in the eyes of the terrorists,” Mr. Bush said. “Another voter was asked, ‘Are you Sunni or Shia?’ He responded: ‘I am Iraqi.'”

Democrats who had hoped to put Mr. Bush on the defensive have instead seen a slight uptick in his popularity and increasing confusion among their own party members on the issue: The minority leader of the House of Representatives, Rep. Nancy Pelosi, of California, publicly embraced Mr. Murtha’s call to redeploy American troops outside Iraq even as the minority whip, Rep. Steny Hoyer, of Maryland, opposed it.

Democrats were also embarrassed when their party’s chairman, Howard Dean, said in a December 5 radio interview, “the idea that we’re going to win the war in Iraq is an idea that is just plain wrong.” Senator Lieberman, a Democrat of Connecticut, responded the following day by saying that those who undermine the president’s credibility during a time of war “do so at our nation’s peril.”

Mr. Bush reached out to his critics last night, asking those who oppose the war not to despair.

“I know this war is controversial,” Mr. Bush said. “Yet being your president requires doing what I believe is right and accepting the consequences. And I have never been more certain that America’s actions in Iraq are essential to the security of our citizens, and will lay the foundation of peace for our children and grandchildren.”

Anticipating last night’s speech, Democrats sought to keep the focus on Mr. Bush’s decision in October 2001 to let the National Security Agency spy on international phone calls and e-mails between people inside American borders without court authorization. The program was first reported Saturday in the New York Times.

Senator Kennedy, a Democrat of Massachusetts, issued a statement yesterday calling the intelligence gathering program, “a quest for absolute power.” Several other Democrats and at least two Republicans also expressed concern. The Republican chairman of the Senate Judiciary Committee, Senator Specter, of Pennsylvania, said he intends to hold a hearing on the issue.

In seeking to boost support for the war, Mr. Bush said American troops are succeeding in establishing a lasting democracy in Iraq. He pointed to last week’s elections, in which a reported 70% of the country’s 15 million registered voters took part, and said America is moving ahead in helping rebuild the Iraqi economy, despite earlier setbacks.

Mr. Bush said he is determined to complete the mission.

“To retreat before victory would be an act of recklessness and dishonor, and I will not allow it,” he said.

Democrats signaled that they would not let up on Mr. Bush over a perceived threat to civil liberties in his prosecution of the war on terror when they blocked a vote Friday on reauthorization of the USA Patriot Act. The bill, which originally passed the Senate by a vote of 98 to 1, is set to expire at the end of the month.

Some analysts have suggested that Mr. Bush and his party, which has been rocked in recent months by ethics scandals, complaints about a slow response to Hurricane Katrina, and a mounting death toll in Iraq, stands in a precarious position politically.

“Americans still have doubts about how we got in and about how forthright the president has been; there’s still concern about White House leaks and uncertainty about Republicans on Capitol Hill and whether they can pass legislation,” the editor of the Rothenberg Political Report, Stuart Rothenberg, said. “I think the president is in a very difficult position.”

But Mr. Bush, striking a characteristic appeal to ideals, closed his speech with a note of optimism that he tied to the holiday season.

“We pray for the safety and strength of our troops,” Mr. Bush said. “We trust, with them, in a love that conquers all fear, and a light that reaches the darkest corners of the Earth. And we remember the words of the Christmas carol, written during the Civil War: ‘God is not dead, nor does he sleep; the wrong shall fail, the right prevail, with peace on Earth, good will toward men.'”