Tony Blair has said that he had "no illusions" that Abu Musab al-Zarqawi's death would alone lead to stability in Iraq but welcomed it as a blow to Al-Qaeda everywhere.
Blair, speaking at his monthly press conference in London, said the death of the leader of Al-Qaeda in Iraq undercut efforts by the Islamist network to sabotage international efforts to build democracy in Iraq and Afghanistan.
"The death of al-Zarqawi is a strike against Al-Qaeda in Iraq and therefore a strike against Al-Qaeda everywhere," Blair said Thursday.
"We should have no illusions. We know they will continue to kill, we know there are many, many obstacles to overcome," Blair said.
"But they also know that our determination to defeat them is total," he said.
His death was significant because Zarqawi was more than a figurehead, Blair said. "I don't think there is any doubt that he was a hands-on leader of Al-Qaeda in Iraq."
It is also important because he was "the most vicious prosecutor" of violence in Iraq which is designed to "stifle" the fledgling democratic government of Iraqi Prime Minister Nuri al-Maliki.
Blair portrayed Iraq as part of the broader war against terrorism, which began with the US-led war against Al-Qaeda and its Taliban host government in Afghanistan following the September 11, 2001 attacks.
Critics, however, have accused London and Washington of fueling Islamist extremists with the launch of the war in Iraq in March 2003, one that has cost Blair and US President George Bush heavily in public support.
"In Iraq and Afghanistan, Al-Qaeda has taken a stand," said Blair.
"They know that if progress and democracy take root in those two previously failed and terrorised states, then their values of violence and hatred against those who disagree with them will in turn be uprooted," Blair said.
"That's why they fight and why they will continue to fight very hard," he said.
"But it is also why we should fight back and do so as a unified international community, putting behind us the divisions of the past and united under the United Nations mandates in both Iraq and Afghanistan," he said.
The US-led invasion triggered opposition throughout the world, including in Europe.
"For three years, Al-Qaeda have sought to murder innocent people, promote sectarian killing and wreck the democratic process in Iraq," he said.
"This terrorism is a global movement. Their attack in Iraq has only ever been part of a wider attack that they have carried into conflicts and countries the world over.
"Indeed, there is barely a major nation in the world that has not felt the outreach of their evil.
"Defeat them in Iraq and we will defeat them everywhere," Blair said.
"We need to do so armed, of course, with weapons, but also with one simple idea -- that where people want to live in freedom and be governed by democracy, they should be able to do so and the world should stand united behind them."
"In Iraq today, that idea has shown its worth."
Blair hailed the nomination Thursday of candidates to head Iraq's interior, defense and national security ministries, completing the formation of the country's democratic government that began with elections late last year.
Prime Minister Nouri Maliki's naming of the ministers was a sign of "a new spirit to succeed", said Mr Blair.
"Our task, obviously, is to turn that spirit, that willingness, that desire to succeed into effective action," he said.
"If we are able to do so, then we will have accomplished something that goes far beyond the borders of Iraq."