Invading Iraq was the right thing to do, President Bush said Monday, because even though weapons of mass destruction remain unfound, allowing the country to possibly transfer weapons capability to terrorists was not a risk he was willing to take.

"Although we have not found stockpiles of weapons of mass destruction, we were right to go into Iraq," Bush said during a trip to the Oak Ridge National Laboratory (search) in Tennessee. The trip was designed to showcase a victory in the Bush administration's campaign against weapons of mass destruction.

Bush inspected a display of nuclear weapons parts and equipment, including assembled gas centrifuges for uranium enrichment, shipped from Libya to America in March as part of an agreement with Muammar al-Qaddafi (search) to end his country's nuclear weapons program.

"We removed a declared enemy of America who had the capability of producing weapons of mass murder and could have passed that capability to terrorists bent on acquiring them. In the world after September 11th, that was a risk we could not afford to take."

The president offered a broad new defense of the March 2003 invasion of Iraq three days after the release of a Senate report that harshly criticized unsubstantiated intelligence cited in the run-up to the war in Iraq.

The key U.S. assertions leading to the invasion — that Saddam Hussein (search) had chemical and biological weapons and was working to make nuclear weapons — were wrong and were based on false or overstated CIA analyses, a scathing Senate Intelligence Committee (search) report asserted Friday.

Intelligence analysts fell victim to "group think" assumptions that Iraq had weapons when it did not, the bipartisan report concluded. Many factors contributing to those failures are ongoing problems within the U.S. intelligence community, which cannot be fixed with more money alone, it said.

Without directly acknowledging the intelligence was flawed, Bush said a wide array of government leaders, from members of the Clinton administration to lawmakers to the U.N. Security Council, had studied the same intelligence and "saw a threat."

During the Clinton administration, official U.S. policy toward Iraq became "regime change" — a stance that sought the ouster of Saddam, Bush noted.

But Saddam refused to open his country to inspections, he said.

"So I had a choice to make: either take the word of a madman or defend America. Given that choice I will defend America."

Bush has used similar rhetoric in speeches for months, but the words took on added significance in light of the latest report condemning the Iraq intelligence.

Upon seeing the nuclear weapons parts and equipment from Libya, Bush called them "sobering evidence of a great danger."

It was the White House's second effort to shine a spotlight on the Libyan victory. Several months ago, the White House arranged a tour of the equipment for journalists.

Bush said Libya's decision to scrap its nuclear ambitions and do away with its long-range missiles was the result of "quiet diplomacy" by the United States, Great Britain and the Libyan government. But it also was the result of outspoken public denunciations of nations that seek to threaten the world with nuclear and other weapons, he said.

He said the world knows that doing so carries serious consequences and that the "wise course is to abandon those pursuits."

And Bush said his administration was doing everything possible to avert the attacks he said terrorists are now plotting.

For months, Bush has been highlighting his threefold strategy for fighting terrorists and those who threaten to use chemical, biological or nuclear weapons: taking the fight to the enemy, coordinating with other nations to isolate terrorists and advancing democracy, especially in the Middle East.

As the November election nears, Bush wants voters to compare situations in such nations as Afghanistan, Iraq and Libya to the way they were three years ago, when the militant Taliban still ruled Kabul, Saddam was still in power in Baghdad and Libya was still supporting terrorism and spending money to acquire weapons of mass destruction.

The White House has long portrayed Libya's pledge to abandon programs to develop weapons of mass destruction as affirmation of Bush's hard-line strategy on arms proliferation. It suggested the U.S.-led war in Iraq helped convince al-Qaddafi that he should act.

Democrats, however, dismiss any such claim, saying instead it was the softer hand of diplomacy that helped score the turnaround in Libya.

"This is a real success for American foreign policy that happened on President Bush's watch," said Flynt Leverett, a foreign policy analyst at the Brookings Institution (search). "But what's maddening is that [administration officials] are misconstruing what produced this outcome. It was not Iraq, but diplomacy that started under [former President] Clinton."

The diplomatic efforts, under way since the 1990s, involved Libya's decision to accept responsibility for the 1988 bombing of an American airliner over the Scottish town of Lockerbie (search), pay compensation to the families of the 270 people killed and dismantle its weapons programs.

In March, the Energy Department, which oversees Oak Ridge, displayed 48 crates and boxes containing equipment used to make nuclear bomb fuel from uranium.

Libya got the equipment from an underground supply network headed by Abdul Qadeer Khan (search), a top scientist in Pakistan's nuclear weapons program.

Bush's trip to Tennessee was his 10th presidential visit to the state. He carried Tennessee in the 2000 election over favorite son Al Gore, but he's not taking Tennessee's 11 electoral votes for granted this year.

First lady Laura Bush is scheduled to give an address in Nashville on Thursday.

The Associated Press contributed to this report.