John Forbes Kerry accepted the Democratic presidential nomination Thursday night, offering himself to Americans as a decorated Vietnam War veteran who saw the horrors of war firsthand as a young man, and who nearly four decades later is ready to defend the country with more vigilance and better judgment than President Bush.

Asserting that America is in "a global war on terror against an enemy unlike any we have ever known before," Kerry repeatedly challenged Bush's credibility, and charged that the Republican incumbent presents a pose of strength but not the reality.

"In these dangerous days, there is a right way and a wrong way to be strong. Strength is more than tough words," Kerry said, one of several taunts of the incumbent laced throughout the address. "After decades of experience in national security, I know the reach of our power, and I know the power of our ideals."

The concluding night of the Democratic convention, held in the nominee's native city, was a festival of flag-waving martial imagery and language, putting Kerry's war experiences and friends on bright display. After being introduced by former senator Max Cleland (Ga.), who was badly maimed in Vietnam, Kerry shared embraces with former Navy Swift boat comrades lining the stage.

"I am John Kerry, and I am reporting for duty," he declared with a salute.

With the presidential election 95 days away, Kerry's hour before a nationally televised audience was dominated by national security, with even the Democratic Party's traditional emphasis on domestic issues harnessed to his larger argument about the war on terrorism.

"As president," Kerry said, "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."

In one of his sharpest lines against Bush, Kerry said his brand of leadership "starts by telling the truth to the American people. That is my first pledge to you tonight: As president, I will restore trust and credibility."

Although Kerry had said he would avoid a negative tone, the crowd at FleetCenter was thrilled with each departure from the stated plan. Kerry took a signature line of Bush's from four years ago -- a promise to the military that "help is on the way" -- and turned it into a mocking refrain. In Kerry's version, he said he would actually deliver on the promise to such groups as veterans and struggling middle-class families.

Although the mood inside the auditorium was more boisterous than on the three previous nights, Kerry's delivery was in keeping with his traditional stump style. His words came out in his usual baritone cadences -- perhaps a bit more rapidly than usual -- without emotional peaks and valleys. The 55-minute speech was interrupted 43 times for applause. "America can do better," he said at one point.

The deeply biographical thrust of the speech had a special purpose for Kerry, who according to polls and his own strategists has not yet established a personal connection with Americans. His children spoke of a loving and emotional father. Singer Carole King performed "You've Got a Friend."

He spoke not only of his now-familiar Vietnam story, but also of his childhood, his faith and family, and the workings of his mind.

"Now I know that there are those who criticize me for seeing complexities," he acknowledged. "And I do, because some issues just aren't all that simple. Saying there are weapons of mass destruction in Iraq doesn't make it so. Saying we can fight a war on the cheap doesn't make it so. And proclaiming 'mission accomplished' certainly doesn't make it so."

Although that was one of several criticisms of Bush's timing in launching war and his preparation for the aftermath, in other ways Kerry sought to portray himself as more willing to move robustly against potential enemies. For instance, he criticized the Bush administration for leaving U.S. ports vulnerable -- "95 percent of our container ships" arrive without being physically inspected -- and said he would increase military spending to expand the armed forces by "40,000 active-duty troops," not for Iraq service, "but to strengthen American forces that are now overstretched, overextended and under pressure."

For the most part, however, this was not a programmatic address but a statement of values.

Kerry advisers have said this week that they believe polls showing Bush with an approval rating below 50 percent make clear that a majority of Americans are ready to fire the incumbent. But they acknowledge that a majority have not decided they are ready to hire the challenger, and that Kerry's most important hurdle is presenting his life story, values and personality in a way that leaves voters comfortable. As in the primaries last winter, when his come-from-behind performance earned him the right to stand at the podium here, Kerry made war the theme to unify his biography, his indictment of Bush and his own leadership values.

"As president, I will wage this war with the lessons I learned in war," Kerry declared. "Before you go to battle, you have to be able to look a parent in the eye and truthfully say: 'I have tried everything possible to avoid sending your son or daughter into harm's way. But we had no choice. . . . We had to protect the American people -- fundamental American values -- against a threat that was real and imminent.' " The speech moved systematically to address the main criticisms of him. To the assertion that he is too liberal, Kerry noted that he broke with members of his party to support deficit-reduction measures in the 1980s. To the criticism that he is too aloof, Kerry flashed a moment of corniness, noting that he was born in a Colorado hospital in "the West wing." To charges that he does not share traditional values, Kerry said, "I don't wear my religion on my sleeve, but faith has given me values and hope to live by from Vietnam to this day, from Sunday to Sunday. I don't want to claim that God is on our side. As Abraham Lincoln told us, 'I want to pray humbly that we are on God's side.' "

He also came to his vice presidential nominee's defense, addressing Bush's suggestion that Edwards is unprepared for the oval office. "This son of a millworker is ready to lead," Kerry said. "And next January, Americans will be proud to have a fighter for the middle class to succeed Dick Cheney."

Kerry portrayed the election not only as the most important of his lifetime, but one that offers voters the clearest of choices on virtually every issue of the day. He promised to raise taxes for only 2 percent of Americans, provide better health coverage, fairer trade and more education assistance.

Fashioning himself as a centrist like Bill Clinton did 12 years ago, Kerry promised to balance the budget and pay for most of his agenda by repealing tax cuts only for those making $200,000 or more. He also made a pledge to seniors watching. "We believe in the family value expressed in one of the oldest Commandments: 'Honor thy father and thy mother.' As president, I will not privatize Social Security. I will not cut benefits. And together, we will make sure that senior citizens never have to cut their pills in half because they can't afford life-saving medicine."

Near the end, Kerry directed his words to an audience of one: Bush. "I want to address these next words directly to President George W. Bush: In the weeks ahead, let's be optimists, not just opponents. 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."

With an emphasis on national security rare for a Democratic nominee, Kerry promised to immediately adopt the 9/11 commission's recommended reforms for U.S. intelligence systems, "so policy is guided by facts, and facts are never distorted by politics."

Speaking to a country profoundly transformed by the Sept. 11, 2001, terrorist attacks, Kerry told Democrats gathered here in his home town that he would lead a strong military that would never allow another nation or international institution to block U.S national-security action. "Let there be no mistake: I will never hesitate to use force when it is required," Kerry said.

The nominee's prime-time speech ended a day, and convention, dedicated to eradicating the party's historic weakness with voters on national security.

There was Willie Nelson singing about the promised land as a gospel choir swayed and a crowd of 5,000 waved U.S. flags that created a welcome breeze in the packed arena. Nelson gave way to Madeleine K. Albright, Clinton's secretary of state and a symbol of the multi-lateralism Kerry preached Thursday night. Kerry will "destroy terrorists around the world," she said.

The day was also full of personal testimonials that covered his long career of public service, from fellow veterans in Vietnam to U.S. senators and his two daughters, Vanessa and Alexandra.

"And let me tell you this, when he loves you -- as he loves me and my sister and his family, as he loves the men who fought beside him -- there is no sacrifice too great. When he cares for you, as he cares for this country, there are no surer hands, and no wiser heart," Alexandra Kerry said in introducing her father.

In a video guided by Steven Spielberg and narrated by Morgan Freeman, Kerry shared how he "cried like a baby" at his daughters' births and credits his life today to the "grace of a higher being." With a mix of real and imposed clips, Kerry's rescue of Special Forces soldier Jim Rassmann from the river in the Mekong Delta was re-created for the prime-time audience.

Cleland, a veteran who left the military with no legs and one arm, introduced Kerry as an "authentic American hero" who braved death for his crewmates in Vietnam and dedicated his life to national service in the aftermath. "The Bible tells me there is no greater love has a man than to lay down life for his friends," Cleland said. "John's fellow crewmates . . . are living testimony to his leadership, his courage under fire."

Moments earlier, Rassmann, one of several crewmates appearing on Kerry's behalf at this convention, said: "Nobody asked me to join this campaign. I volunteered, and not just because 35 years ago John Kerry saved my life."

It was after this that Kerry snaked through a sea of bobbing white Kerry signs, to the sounds of Bruce Springsteen's "No Retreat, No Surrender." One woman screamed, "Thank you, Jesus!"

It will be several days before pollsters have a handle on how the national audience reacted, but on the floor there was no doubt.

"I thought he did what he was supposed to do," said Eric Cowan, 32, a delegate from Arkansas. "He gave us a reason to vote for him, and he didn't bore us the way the Republicans said he would. I hope all of America is as excited as I am."

John F. Kerry, with John Edwards, said: "Strength is more than tough words. . . . I know the reach of our power, and I know the power of our ideals."Would-be first lady Teresa Heinz Kerry revels in the balloon drop after her husband's acceptance speech."You see that flag up there," Kerry said. ". . . I fought under that flag." The presidential nominee referred to combat lessons he learned in Vietnam.Florida delegates take advantage of final photo opportunities at FleetCenter. The four-day convention in Boston drew together almost 5,000 delegates under extraordinary security.Ros Samuels of Montclair, N.J., lends her support. Democrats chose a song by Garden State native Bruce Springsteen to accompany Kerry's entrance.