Vice President Dick Cheney (search) accused John Kerry (search) on Wednesday night of a dangerous "habit of indecision" hardly befitting a commander in chief. President Bush, he said, has led with strength and conviction.

"A senator can be wrong for 20 years, without consequence to the nation. But a president always casts the deciding vote," Cheney told cheering delegates who greeted him with chants of "four more years!"

Accepting his party's nomination for a second term, Cheney paid brief homage to Kerry's service in Vietnam and then said he has been wrong on foreign policy in the three decades since.

"Even in this post-9/11 period, Senator Kerry doesn't appear to understand how the world has changed," Cheney told delegates packed into Madison Square Garden and millions of voters watching at home.

Cheney's task Wednesday night was twofold: talk up the president and take apart the record of the man challenging him. His mostly somber speech at times left delegates laughing, often at Kerry's expense, and Cheney's lopsided smile broke into a full-fledged grin.

Echoing accusations he and President Bush have made repeatedly on the campaign trail, Cheney accused Kerry of taking two sides in a series of issues, including war with Iraq and on No Child Left Behind (search), the president's education initiative.

"His back-and-forth reflects a habit of indecision, and sends a message of confusion," he said in one of his harshest critiques yet of the Massachusetts senator who is challenging Bush for the presidency. "Sen. Kerry says he sees two Americas. It makes the whole thing mutual. America sees two John Kerrys."

Delegates responded with chants of "flip flop, flip flop" and some waved flip-flop sandals.

Kerry's campaign has said that after congressional approval, Bush mishandled both the Iraq war and the education law.

On national security, Cheney, who received five deferments from service in Vietnam, noted Kerry's decorated service. "And we honor him for it," Cheney said.

He then launched into an extended critique of Kerry's record, saying it is on national security where the differences between Bush and Kerry are sharpest.

"Time and again Senator Kerry has made the wrong call on national security," Cheney said.

Kerry, he said, wants to please allies rather than lead the world with strength.

"George W. Bush will never seek a permission slip to defend the American people," he said to thunderous applause from delegates shouting "USA! USA!" and hoisting signs that read "Let Freedom Reign."

Cheney's vice presidential rival, Democratic Sen. John Edwards, responded that Democrats would do better than the current administration at home and abroad. "There was a lot of hate coming from that podium tonight," he said in a statement. "What John Kerry and I offer to the American people is hope."

The vice president delivered his remarks in his trademark stern style -- less the thundering politician than the college professor he once set out to be.

Dropping some of his more strident rhetoric about why the administration went to war, Cheney said the United States "dealt with a gathering threat" from Saddam Hussein and restored freedom to the Iraqi people. "Seventeen months ago, he controlled the lives and the fortunes of 25 million people. Tonight he sits in jail."

The vice president made no mention of Al Qaeda leader Usama bin Laden, still at large.

And he gravely warned of threats on the horizon, an enemy "whose hatred of us is limitless, armed with chemical, biological, or even nuclear weapons."

Cheney defended the Bush record on domestic issues -- education, taxes, the economy and health care.

And he spoke of his grandfather, who never went to high school but saw nothing strange about sending word to President Roosevelt that a boy named Richard Cheney had been born on his birthday.

"My grandfather believed deeply in the promise of America, and had the highest hopes for his family. And I don't think it would surprise him all that much that a grandchild of his stands before you tonight as vice president of the United States," said Cheney, 63.

Cheney has attended at least a portion of each session of the convention, to the delight of admiring delegates. Outside Madison Square Garden, he's spent his time with friends, family and Republican donors.

Throughout the Bush administration, he has been a magnet for critics, with detractors accusing him of pushing the country into war with Iraq, holding secret meetings with polluters and backing unaffordable tax cuts that mainly aid the wealthy. His former leadership of Halliburton Co., which is now doing major business in Iraq, also continues to be a source of controversy.

It appears to have taken a toll in public opinion. A survey released this week found his approval ratings at an all-time low.

But Cheney appears unconcerned with his own popularity. He long ago considered and rejected his own presidential run, and friends say he is devoted to Bush's best interests.

Cheney was introduced by his wife of 40 years, Lynne, a well-known conservative voice in her own right before her husband was elected vice president.

The Cheneys' two daughters, Liz and Mary, and their three granddaughters watched from seats just above the convention floor. Liz and her husband, Phil Perry, and their daughters joined the Cheneys on stage after the speech, though Mary did not.

In a rare split with conservatives, last week Cheney spoke of Mary's homosexuality and said states should have the right to approve same-sex marriages.

Early in Cheney's remarks, a middle-age woman attempted to disrupt the speech and was removed from the hall by security personnel.

Cheney will remain in New York to watch Bush deliver his own address Thursday, then leave early Friday for two days of campaigning, traveling to Oregon, Nevada and New Mexico.