Blair flew into the dusty moonscape of southern Afghanistan in the cockpit of a Royal Air Force Hercules transport plane to chat about anti-Taliban operations with members of the NATO force at the Camp Bastion base.
"Here on this extraordinary piece of desert is where the future of world security in the early 21st century is going to be played out," Blair told several hundred troops in a speech before departing for Kabul.
Despite recent resistance from Taliban fighters in the south which has cost 36 British lives this year, he said they would overcome through their "determination, courage and absolute will."
"When you defeat them, you are defeating them not just on behalf of the people of Afghanistan but our country, Britain, and the wider world," he said at the base in Helmand province.
As troops in desert fatigues clamoured to have photographs taken with Blair, Sgt Chris Hunter from the Royal Marines told him: "I think a point that needs to be made back home is that the lads want to be here."
Blair was whisked to Kabul by the Hercules and then a US Air Force Black Hawk helicopter for talks with Hamid Karzai at his presidential palace, and recommitted Britain to the Afghan leader's reform and reconstruction programme.
But he increased the pressure on NATO members ahead of a summit in Latvia this month, urging allies to reengage with Afghanistan by acknowledging the progress made since the Taliban were ousted by US-led forces in late 2001.
The Taliban refused to hand over Osama bin Laden after the September 11 attacks on the United States.
"Now is the right time to bring into sharp focus the need to stay with the Afghans as they make their journey to progress, and rediscover in ourselves the belief and vision that took us here and that should keep us here until the job is done," he told a joint news conference with Karzai.
Asked whether NATO allies had lost focus because of the increased violence, Blair accepted that recent Taliban resistance had been stronger than expected over the summer but said Britain and the west were committed.
"We came to Afghanistan because it was obvious that the problem in Afghanistan had become a problem for the world. We have got to stay committed for our own security, not just for the sake of the Afghan people," he said.
Blair praised the work of Karzai's government over the last five years and contrasted his visit Monday with his previous trip to Afghanistan in January 2002 when he met officials in a disused Russian airbase hangar.
Karzai highlighted progress in the conflict-scarred country's economy and said he was sure the international community would "stay with us until we are firmly on our own feet."
The British commander of NATO's International Security Assistance Force, General David Richards, accepted that Taliban activity had increased earlier this year but dismissed suggestions that the war here was not winnable.
"Today there is a different atmospheric about the place. We know the Taliban are concerned and we are on the rise," he said, adding they needed to "lock on to" the change and convince people of the merit of the international presence.
Blair's visit comes after a two-day trip to neighbouring Pakistan where his talks with President Pervez Musharraf focused heavily on countering extremism and solving Afghanistan's problems.
President Musharraf called for massive investment in development in Afghanistan along the lines of the US Marshall Plan to rebuild Europe after World War Two.
Britain has about 5,500 troops in Afghanistan -- the second-largest contingent in the 37-nation, 31,000-strong ISAF force set up to bring stability to the troubled country and aid reconstruction.

Copyright AFP (Agence France-Presse), 2006