President Bush (search) challenged Democratic rival John Kerry (search) on Friday to give a yes-or-no answer about whether he would have supported the invasion of Iraq "knowing what we know now" about the failure to find weapons of mass destruction.

"I have given my answer," Bush told a cheering crowd. "We did the right thing and the world is better off for it."

Kerry's campaign said he already had answered the question — and then criticized Bush's handling of the war anew.

Kerry voted to give Bush the authority to send troops to Iraq (search). "As John Kerry has said previously, it was right to hold Saddam Hussein accountable and we're glad he's gone," said Susan Rice, the Democrat's senior adviser for national security affairs.

She said that Bush had "rushed into war without our allies, without a plan to win the peace and without properly equipping our troops."

With persistent violence and climbing casualties, Iraq has become a problem for Bush, turning what once was believed to be an asset for his re-election campaign into a vulnerability. Only about four in 10 Americans support the president's handling of Iraq, polls show, and just a third say he has a clear plan to deal with the situation. Nevertheless, Bush tried to put Kerry on the defensive.

"Now, there are some questions that a commander in chief needs to answer with a clear yes or no," Bush said. "My opponent hasn't answered the question of whether, knowing what we know now, he would have supported going into Iraq. That's an important question and the American people deserve a clear yes or no answer."

Bush said America was safer because Saddam Hussein sits in a prison cell. "Even though we did not find the stockpiles that we thought we would find, we did the right thing," the president said. "He had the capability and he could have passed that capability on to our enemies."

Bush also said Kerry's criticism of his Iraq policies merely shows the Democrat doesn't understand who America is up against.

"My opponent said something the other day I strongly disagree with — he said that going to war with a terrorist is actually improving their recruiting efforts," Bush said, referring to a remark Kerry made Monday.

"Now, that's upside-down logic," Bush said. "It shows a misunderstanding of the enemy."

Anti-American forces were training in the 1990s, Bush said. "They don't need an excuse for their hatred, and it is wrong to blame America for the anger and evil of the killers."

"We don't create terrorists by fighting back. We defeat the terrorists by fighting back," he said."

Bush spoke to several hundred cheering supporters at a political picnic.

Kerry, a Democratic senator from Massachusetts, said Monday, "The policies of this administration, I believe and others believe very deeply, have resulted in an increase of animosity and anger focused on the United States of America."

"The people who are training terror are using our actions as a means of recruitment," he said.

The Democrat has pointed out that Defense Secretary Donald H. Rumsfeld asked in a memo earlier this year whether terrorists were being created faster than the United States could capture and kill them.

Bush's trip to New Hampshire offered a glimpse of high emotions on both sides of the presidential election.

Two groups tried to shout each other down as Bush's motorcade rounded a bend onto a farm, one contingent shouting "Four more years!" and the other "Three more months!"

As always, Bush's team carefully weeded out the dissenters, and "four more years!" was the only cry heard in a pasture-turned-political venue here.

But polls show this state is a dead heat this year and Bush tried to tip it back his way with his seventh visit as president.

From New Hampshire, Bush flew to his family's home in Kennebunkport, Maine, where his nephew, George P. Bush, is to be married on Saturday.