With the nation at war against an enemy "unlike any we have ever known," John Kerry (search) accepted the Democratic presidential nomination Thursday by vowing to defend the United States as commander-in-chief as he defended it during the Vietnam War.

"Let there be no mistake: I will never hesitate to use force when it is required. Any attack will be met with a swift and certain response. I will never give any nation or international institution a veto over our national security. And I will build a stronger American military," Kerry said in his address to the 44th Democratic National Convention (search) from the podium of Boston's FleetCenter at a little after 10 p.m. EDT.

On Thursday, convention delegates officially made Kerry's running mate, John Edwards, the Democratic nominee for vice president.

Thursday night's show was the culmination of a four-day rally where party loyalists have been pumping up the man they hope can oust George W. Bush (search) from the White House in November.

The Massachusetts senator on Wednesday night collected more than enough votes — in fact, all but a few dozen of the 4,353 delegate votes up for grabs — to clinch the party's top prize.

The candidate was introduced by his daughters, Alexandra and Vanessa.

"When he teaches you, by the life he has led, as he has taught me and my sister all of our lives, there is no better lesson: That the future of this country is not only his life's work. It's mine and yours. It is all of our life's work, all of us," said Vanessa Kerry.

Vanessa said "integrity" describes the value that encapsulates her father and what he can offer the country.

Kerry's "band of brothers" — crewmates from this Vietnam days — took the stage before Kerry spoke to honor the man they said is a true leader.

Jim Rassmann, whose life Kerry saved during Vietnam 35 years ago, told the crowd he wasn't speaking in support of Kerry because he was asked to, but because he volunteered.

"I volunteered because I've seen John Kerry in action. I know his character. I've witnessed his bravery and leadership under fire. And I know he will be a great commander-in-chief," Rassmann said, joined by 12 other men who were Kerry's Vietnam crewmates. "Any one of these 12 guys will tell you, in a tight situation, when your whole future — your whole life — depends on the decisions of one man, you can count on John Kerry.

"And that's why this band of brothers is here tonight."

Former Georgia Sen. Max Cleland (search) — a triple amputee from Vietnam — said Kerry's service to America only began with his service in Vietnam and that "there's no greater act of patriotism" than risking one's life for one's country.

"My fellow Americans — John Kerry has never let me down. He'll never let you down. He is an authentic American hero. He is the next captain of our ship of state. And he will be the next president of the United States."

Kerry received a raucous ovation and sustained applause when he entered to the sounds of Bruce Springsteen's "No Surrender." Reminiscent of the State of the Union address when the president shakes hands with members of Congress while he walks down the House floor to the dais, Kerry entered the floor from the back and shook hands and high-fived supporters along the way.

Reporting for Duty

Kerry took several minutes to calm the crowd that chanted "Kerry, Kerry" and flooded the room with blue and white Kerry signs.

"I am John Kerry and I am reporting for duty," the former sailor said.

Speaking to his values, Kerry said he will ask "hard questions and demand hard evidence" as president. He vowed to reform immediately the U.S. intelligence system that has come under so much criticism for failure to detect and prevent the Sept. 11, 2001, terror attacks.

He also included an oft-repeated line from the campaign trail.

"I will bring back this nation's time-honored tradition: the United States of America never goes to war because we want to, we only go to war because we have to," he said.

Saying this is "the most important election of our lifetime" amid "dangerous days," the junior Bay State senator said not only do the challenges abroad need to be dealt with but so do challenges here at home, such as rising health-care costs.

"We can do better and we will. We're the optimists. For us, this is a country of the future. We're the can-do people," Kerry said. "We need to make America once again a beacon in the world. We need to be looked up to and not just feared."

Kerry also vowed to implement immediately the recommendations made last week by the independent commission probing the Sept. 11, 2001 (search), terror attacks and once again spoke about the values he says will steer his path at 1600 Pennsylvania Avenue.

"My fellow citizens, elections are about choices. And choices are about values," he said. "In the end, it's not just policies and programs that matter; the president who sits at that desk must be guided by principle."

Kerry: I 'Will Never Mislead Us'

Vowing to use the lessons he learned while serving in the Vietnam War, Kerry said the "only justification" for going to war is when there is no other choice to help protect the American people from a "real and imminent" threat.

"I will be a commander-in-chief who will never mislead us into war," Kerry said. "And on my first day in office, I will send a message to every man and woman in our armed forces: You will never be asked to fight a war without a plan to win the peace."

In Iraq, the United States needs to have the burden shared to reduce the cost to American soldiers and taxpayers, Kerry said, and to get the troops home faster.

"Here is the reality: That won't happen until we have a president who restores America's respect and leadership — so we don't have to go it alone in the world," the senator said. "And we need to rebuild our alliances, so we can get the terrorists before they get us."

Kerry vowed that if elected, his administration will add 40,000 active-duty troops to bolster American forces and will double special forces to conduct anti-terrorist operations as well as provide troops with the newest weapons and technology to save their lives and win the battle.

"As president, I will fight a smarter, more effective War on Terror. We will deploy every tool in our arsenal: our economic as well as our military might; our principles as well as our firepower."

On the Domestic Front

Aside from the War on Terror (search) promises, the Democratic candidate maintained the Democrats' tone of optimism. He promised to keep more American jobs from going overseas, not to privatize Social Security or cut senior citizen benefits, to provide new incentives to spur the manufacturing sector, to further fair-trade laws, to roll back tax cuts for the wealthiest Americans, to provide for smaller class sizes and to give a tax credit to families for each and every year of college.

Kerry also promised to end the United States' dependence on Mideast oil — a theme echoed by many Democratic lawmakers this week

"I want an America that relies on its own ingenuity and innovation — not the Saudi royal family," Kerry said. "And our energy plan for a stronger America will invest in new technologies and alternative fuels and the cars of the future — so that no young American in uniform will ever be held hostage to our dependence on oil from the Middle East."

Kerry — in an about-face from the direction the Kerry camp apparently told other speakers to take this week in their remarks — directly addressed the current president.

"In the weeks ahead, let's be optimists, not just opponents," Kerry challenged Bush. "Let's build unity in the American family, not angry division. Let's honor this nation's diversity; let's respect one another; and let's never misuse for political purposes the most precious document in American history, the Constitution of the United States.

"My friends, the high road may be harder, but it leads to a better place. And that's why Republicans and Democrats must make this election a contest of big ideas, not small-minded attacks."