Two years to the day after the start of the U.S. led invasion of Iraq, President Bush defended his decision to go to war. "Now, because we acted, Iraq's government is no longer a threat to the world or its own people. Today the Iraqi people are taking charge of their own destiny," he said.

Anti-war activists in Europe remain unconvinced that the March 2003 invasion was justified. On Saturday, tens of thousands of demonstrators gathered in cities across Europe to demand an end to the U.S. occupation of Iraq.

A crowd of tens of thousands marched through central London, while an estimated 15,000 people marched in Istanbul to protest the U.S. presence in Iraq. Others protests were held in Sweden, Spain and Italy.

Demonstrators, including this man, marching through central Rome, called for the complete withdrawal of troops from Iraq.

He says he marched against the invasion two years ago and returned today for the same reasons. He says war is completely useless and only produces more war. Although the official war only lasted one month and 20 days, he says the death toll has continued to rise since then.

Recent polls show that Americans have mixed feelings about the war. According to a Washington Post-ABC News poll, a majority of those surveyed said they believe the Iraqi people are better off today than they were before the conflict began, but they also said the war was not worth fighting in the first place.

Americans are increasingly skeptical about the growing cost of war - both in human lives and economic terms. The two-year military campaign has cost 1,519 American lives, thousands of non-fatal casualties, and more than $200 billion in emergency spending.

Despite the growing ambivalence about the war, there were only scattered protests across the United States. A small group gathered in Pasadena, California where former U.S. Army soldier Aidan Delgado reminded people not to forget the human cost of war. "Look out and imagine 1,500 people standing here and now imagine them absent," he said.

During his weekly radio address, President Bush paid tribute to the men and women who lost their lives in Iraq, but said until Iraq can successfully defend itself, U.S. forces will remain in the country. The president said Iraqi's new freedom is inspiring democratic reformers across the Middle East and around the world. "Today we're seeing hopeful signs across the broader Middle East. The victory of freedom in Iraq is strengthening a new ally in the war on terror, and inspiring democratic reformers from Beirut to Tehran," he said.

Against the backdrop of political progress, insurgents in Iraq continue to target U.S. and international forces as well as Iraqis. An attack in the northern Iraqi city of Kirkuk left three policemen dead and seven others wounded. Meanwhile, outside the heavily fortified Green Zone in Baghdad a suicide attacker detonated a car bomb killing himself. There were no reports of additional casualties.