Hours after detailing his new strategy to wrest Iraq from the grip of unrelenting insurgent violence, President Bush arrived in Fort Benning, Ga., Thursday to explain to soldiers why it's necessary to send more than 21,000 additional U.S. troops to Iraq over the next few months.

Meanwhile on Capitol Hill, key administration officials tried to sell the plan to resistant Democrats threatening to put a stop to any troop buildup and weary Republicans willing to give the president one more chance to end the long-running war in the win column.

Democrats and some Republicans say they don't want to risk more American lives helping a nation that doesn't want to help itself. Leaders of the Democratic-controlled Congress were considering options for a nonbinding resolution, to be introduced next week, denouncing the troop increase in Iraq.

But Senate Minority Leader Mitch McConnell, R-Ky., said he would filibuster any efforts to try to stop the president from exercising his authority as commander in chief.

"Congress is completely incapable of dictating the tactics of the war," he said.

Click here to read abut McConnell's filibuster threat.

To repel the onslaught, Bush began a diplomatic mission that included not only consulting with world leaders, like Saudi Arabia's King Abdullah, but appealing to the U.S. public starting with a trip to meet soldiers and their family members at Ft. Benning, where he will also watch an infantry demonstration

Before he left, the president awarded a Medal of Honor, the nation's highest military decoration, to the late Cpl. Jason Dunham, a young Marine who fell on a hand grenade in Iraq, giving his life to save his comrades.

Meanwhile, Secretary of State Condoleezza Rice, Defense Secretary Robert Gates and Joint Chiefs of Staff Chairman Gen. Peter Pace explained to White House reporters their roles in tamping down the Iraq insurgency so U.S. soldiers can start coming home.

"Among Americans and Iraqis, there is no confusion over one basic fact: It is the Iraqis who are responsible for what kind of country Iraq will be. It is they who must decide whether Iraq will be characterized by national unity or sectarian conflict," Gates said. "The president has conveyed to the Iraqi leadership that we will support their good decisions, but that Americans' patience is limited."

"America has to be committed because of the enormous stakes in Iraq and enormous stakes not just for the Iraqi people, but for our interests. We have to remember that an Iraq that is a terrorist safe haven in the Middle East would be devastating to our own interests," Rice told FOX News

Gates announced that the United States not only will beef up its presence in Iraq, but the Pentagon will seek to add 92,000 troops to its overall force structure — 65,000 Army soldiers and 27,000 Marines.

"First, we will propose to make permanent the temporary increase of 30,000 for the Army and 5,000 for the Marine Corps," Gates said. "Then we propose to build up from that base in annual increments of 7,000 troops a year for the Army and 5,000 for the Marine Corps until the Marine Corps reaches a level of 202,000, and the Army would be at 547,000."

Breaking the 'Cycle of Violence'

In a prime-time address to the nation Wednesday night, Bush told the nation that sending more troops to Iraq will help the country "break the current cycle of violence" and "hasten the day our troops begin coming home."

VIDEO: Watch President Bush's Address on His New Iraq Strategy | TRANSCRIPT

The president told Americans that a new strategy — one that includes expanded intelligence sharing, a greater commitment from Iraqis in their future and diplomatic efforts to prevent hostile regional actors from interfering — will usher in a new era, one that will advance, liberty, raise just societies and prevent a "hateful ideology" from taking root.

"Victory will not look like the ones our fathers and grandfathers achieved. There will be no surrender ceremony on the deck of a battleship," Bush said from the White House Library, a room never before used by the president for a public address.

"But victory in Iraq will bring something new in the Arab world — a functioning democracy that polices its territory, upholds the rule of law, respects fundamental human liberties and answers to its people. A democratic Iraq will not be perfect. But it will be a country that fights terrorists instead of harboring them — and it will help bring a future of peace and security for our children and grandchildren," he said.

In remarks at Thursday's House Armed Services Committee hearing, Gates offered assurances that the military command stands behind the president.

"Your senior professional military officers in Iraq and in Washington believe in the efficacy of the strategy outlined by the president last night," he said.

Gates faced a skeptical audience, particularly new House Armed Services Committee Chairman Ike Skelton, D-Mo. In a statement late Wednesday, Skelton dismissed Bush's plan as "three and a half years late and several hundred thousand troops short."

Looking to display party unity, House and Senate Democratic leaders issued a joint statement asserting that Bush's plan places an increased burden on a stretched military and "endangers our national security."

Democrats planned to seek bipartisan support for a resolution that would place Congress on record opposing the troop increase. That effort, though, also underscored Democratic divisions on whether to undo Bush's plan with tougher legislative measures.

"We're not going to babysit a civil war," Sen. Barack Obama, D-Ill., told NBC's "Today" Show.

Obama said the Democratic-controlled Congress would not undercut troops already in Iraq but would explore ways to restrict the president from expanding the mission.

Democrats Blast 'Escalation' of War in Bush's New Iraq Strategy.

Separately, a coalition of labor, anti-war groups and liberal organizations planned to announce a multimillion-dollar advertising and grassroots campaign against the commitment of extra troops.

Bush said now is the time for a change in strategy because "failure in Iraq would be a disaster for the United States." Bush acknowledged prior mistakes in Iraq, noting that U.S. forces "have done everything we have asked them to do." He said where blame lies, it rests with him, but efforts by the U.S. were stymied by limits to the actions Americans could take to secure the area and too few troops to secure neighborhoods that had been cleared of terrorists.

Military commanders approve of Bush's plan, agreeing that too many restrictions on current troop levels in Iraq that prevented success in Baghdad.

The new approach includes sending 21,500 additional U.S. troops — 17,500 to Baghdad and 4,000 to Al Anbar province — to join the 132,000 already there. Five brigades will be deployed to Baghdad and work alongside and be embedded in Iraqi units.

"The increase in military forces will be phased in. It will not unfold overnight. There will be no D-Day. It won't look like the Gulf War," Gates said.

"Our troops will have a well-defined mission: to help Iraqis clear and secure neighborhoods, to help them protect the local population and to help ensure that the Iraqi forces left behind are capable of providing the security that Baghdad needs," Bush told the nation.

He also put Iraqi leaders on notice that the new approach could be a last chance for them to bring order to their nation.

"I have made it clear to the prime minister and Iraq's other leaders that America's commitment is not open-ended. If the Iraqi government does not follow through on its promises, it will lose the support of the American people — and it will lose the support of the Iraqi people. Now is the time to act. The prime minister understands this," Bush said.

The president said that the Iraqi government, led by Prime Minister Nouri al-Maliki, plans to step up to the task by establishing its authority in several areas. The Iraqi government will take responsibility for the security in Iraq's 18 provinces by November, the parliament will pass legislation to share oil revenues among all Iraqis and the government will spend $10 billion of its own money on reconstruction and infrastructure projects that will create new jobs, Bush said.

"To empower local leaders, Iraqis plan to hold provincial elections later this year. And to allow more Iraqis to re-enter their nation's political life, the government will reform de-Baathification laws — and establish a fair process for considering amendments to Iraq's constitution," he said.

Bush said he was instituting some recommendations proposed by the Iraq Study Group, including increasing the number of American advisers embedded in Iraqi Army units, partnering a coalition brigade with every Iraqi Army division and accelerating the training of Iraqi forces.

The president also called for decentralizing reconstruction efforts. Ten units known as Provincial Reconstruction Teams will be expanded to at least 18. Under State Department control, the teams will administer some of the economic aid, including an effort to provide small loans to start or expand businesses.

"These teams bring together military and civilian experts to help local Iraqi communities pursue reconciliation, strengthen moderates and speed the transition to Iraqi self reliance. And Secretary Rice will soon appoint a reconstruction coordinator in Baghdad to ensure better results for economic assistance being spent in Iraq," Bush said.

To oversee the PRTs and other economic support, Rice named Amb. Tim Carney, who formerly served in Haiti, to the new position of coordinator for Iraq transitional assistance.

"He has enormous experience in post-conflict stabilization and reconstruction and development," Rice said.

Dems: Iraq Shouldn't Rely on U.S.

Rice is leaving for the region Friday to build diplomatic support from countries like Saudi Arabia, Egypt, Jordan and other Gulf States that as Bush said "understand that an American defeat in Iraq would create a new sanctuary for extremists — and a strategic threat to their survival."

Rejecting one recommendation of the ISG, Bush did not suggest any diplomatic discussion with Iran or Syria, which he said are offering support to insurgent forces trying to destroy Iraq.

"These two regimes are allowing terrorists and insurgents to use their territory to move in and out of Iraq," Bush said. "We will seek out and destroy the networks providing advanced weaponry and training to our enemies in Iraq."

"Despite many appeals, including from Syria's fellow Arab states, the leaders in Damascus continue to support terrorism and to destabilize Iraq and their neighbors. The problem here is not a lack of engagement with Syria but a lack of action by Syria," Rice said.

"I repeat an offer that I've made several times today," she added. "If Iran suspends its uranium enrichment — which is an international demand, not just an American one — then the United States is prepared to reverse 27 years of policy, and I will meet with my Iranian counterpart any time anywhere. Thus we would have the possibility to discuss every facet of our countries' relations."

The president rejected some Democrats' calls to withdraw from the war, saying "to step back now would force a collapse of the Iraqi government, tear that country apart and result in mass killings on an unimaginable scale."

But he said he did take the advice of Sen. Joe Lieberman, D-Conn., who proposed "a new, bipartisan working group that will help us come together across party lines to win the War on Terror."

The group will look for ways to "mobilize talented American civilians to deploy overseas where they can help build democratic institutions in communities and nations recovering from war and tyranny."

Despite the effort to cast a new day in Iraq, Democratic leaders were having none of what Bush was offering. Senate Majority Whip Dick Durbin, D-Ill., said Iraqis should get used to the Americans not giving an open-ended commitment of support.

"Every time they call 911, we are not going to send more soldiers" to Iraq, Durbin said.

Polling by AP-Ipsos in December found that only 27 percent of Americans approved of Bush's handling of Iraq, his lowest rating yet. The November election was widely seen as a call for a change in direction on Iraq. Durbin criticized Bush for too late recognizing a problem that has been ongoing for four years.

"Tonight President Bush acknowledged what most Americans know ... we are not winning in Iraq ... indeed the challenge is grave and deteriorating," Durbin said. "Twenty thousand American soldiers are too few to end this civil war in Iraq and too many American lives to risk on top of those we've already lost."

Durbin also joined a statement criticizing Bush made with Senate Majority Leader Harry Reid, House Speaker Nancy Pelosi, D-Calif., and House Majority Leader Steny Hoyer, D-Ill.

"The president had an opportunity tonight to demonstrate that he understood the depth of the concern in the country, make a long overdue course correction and articulate a clear mission for our engagement in Iraq. Instead, he chose to escalate our involvement in Iraq's civil war by proposing a substantial increase in the number of our forces there," they said.

The Associated Press contributed to this report.