President Bush says the United States is safer now, five years after the September 11, 2001, terrorist attacks, but some experts disagree.

On September 11, 2001, the United States was struck by the most devastating terrorist attack in its history. Two hijacked planes slammed into the World Trade Center towers in New York, destroying the two buildings. A third plane struck the Pentagon near Washington, while a fourth - due to the bravery of the passengers, who tried to retake control of the plane - crashed into a field in Pennsylvania.  Almost 3,000 people died in those attacks.

Subsequent investigations indicated that al-Qaida, a radical Islamic group led by Osama bin Laden, was responsible for the assaults.

The United States has not had a terrorist attack on its soil since that September day five years ago. But since that time, terrorists struck other parts of the world, including Bali, Turkey, Madrid and London. And just last month, British police foiled an alleged plot to blow up commercial airliners bound for the United States.

In a speech this week  in Atlanta, President Bush talked about the notion of safety.

"Many Americans look at these events and ask the same question: Five years after 9/11, are we safer? The answer is, yes, America is safer.  We are safer because we've taken action to protect the homeland. We are safer because we are on offense against our enemies overseas. We are safer because of the skill and sacrifice of the brave Americans who defend our people," he said.

At the same time, Mr. Bush said, the United States will not be totally safe, until its enemies are defeated.

Experts disagree on whether the U. S. is safer now than five years ago. Danielle Pletka, from the American Enterprise Institute, sides with the president.

"But here is the question that I always like to challenge people back with, when they ask that question. And that is: were we more safe on September 10, 2001? We certainly felt safe, and we felt safe until eight o'clock that morning [September 11]. So, were we more safe? And do we have the information necessary to make those judgments? Or, do we trust our democratically elected government and representatives to actually make those judgments for us. I think that is what we have to do. The fact that there hasn't been another attack does have meaning, and it cannot be dismissed," she noted.

However, former U.S. Assistant Secretary of Defense Larry Korb takes the opposite view.

"What has happened is, particularly with the invasion of Iraq, we have created a lot of al-Qaida wannabees, and there are more people now that are trying to do us harm than there were before we went into Iraq," he explained.  "Certainly, some of the things we have done have made us safer, but on balance, we have created so many more potential attacks that I don't believe that we are safer."

Bush administration officials have rejected any suggestion that the U.S. invasion of Iraq has made the United States and its interests and allies more likely targets for terrorist attacks.

Brian Jenkins is a leading authority on terrorism, working for the RAND Corporation. He says a much more difficult question to answer is, are we safe enough?

"If we look at the terrorist attacks that have occurred around the world since 9/11 and the targets that they have attacked - restaurants, nightclubs, hotel lobbies, train stations, subways - we would have to admit that those same categories of targets are vulnerable in our society," he said. "And so while we have increased security, we have to be realistic about that security and understand that we are never going to be entirely safe."

Jenkins says given the international dimension of the so-called war on terror, that struggle will go on for a very long time.