Prime Minister Gordon Brown affirmed Britain's commitment to Afghanistan on a weekend in which roadside bombs killed five more soldiers, pushing the U.K. death toll past 200.
The grim milestone has reignited debate about the heavy human cost of a conflict the government claims is vital to defeating terrorism but that critics say is unwinnable.
The Ministry of Defense said three soldiers from 2nd Battalion The Royal Regiment of Fusiliers died after they were attacked while on patrol Sunday near Sangin in Helmand Province. They brought Britain's death toll in the country to 204.
Two other British soldiers died Saturday.
Brown said it had been "a very difficult summer," but insisted the troops' presence in Afghanistan was keeping Britain safe.
Thirteen British troops have been killed so far in August, and 22 died in July, Britain's bloodiest month since the invasion of Afghanistan soon after the Sept. 11, 2001, attacks.
"Three-quarters of the terrorist plots that hit Britain derive from the mountain areas of Pakistan and Afghanistan and it is to make Britain safe and the rest of the world safe that we must make sure we honor our commitment to maintain a stable Afghanistan," Brown said.
Others said the price was too high.
"This should never have happened in the first place," said Anthony Philippson, whose son James died in Afghanistan in 2006. He said the war was "a waste of time" and the troops poorly equipped.
Second-largest force
Britain has about 9,000 troops in Afghanistan, the largest international presence after the United States. Most are based in Helmand province, where they face determined Taliban insurgents, and casualties have been rising steadily in the past year.
Separately, the Foreign Office said Sunday that a British man had been killed in Herat, western Afghanistan, but released no other details. The Ministry of Defense said he was a former soldier and British media reported he was working for a private security company.
British troops are part of a 64,000-strong NATO force in the country to bolster the shaky democratic government of President Hamid Karzai and prevent the return of the fundamentalist Taliban, driven from power by the U.S.-led 2001 invasion.
NATO Secretary General Anders Fogh Rasmussen called the rise of Britain's death toll past the 200 mark "a heavy price to pay," but said preventing the return of terrorism in Afghanistan remained "a critical security task."
Britain's armed forces are used to long conflicts and to taking casualties. More than 700 were killed over the 30 years of Northern Ireland's Troubles, and 179 British troops died during a six-year mission in Iraq that ended earlier this year.
Critics: Goals too vague
But critics of the Afghan campaign say the mission is too open-ended, and its goals too vague. At various times British officials have emphasized the need to make Afghanistan a stable democracy, to curb the opium trade and to stop al-Qaida and related groups basing themselves there.
The incoming British army chief said last week that the mission in Afghanistan could last up to 40 years.
The mission faces many unanswered questions, including whether there are enough NATO forces to keep the Taliban at bay, said Gareth Price, head of the Asia program at London think tank Chatham House.
"The exit strategy is to build up the Afghan army so they can do it — but when that will come, who knows?" he said.
Polls suggest Britons are about evenly split between supporters and opponents of the mission.
Graham Knight, whose son Ben was killed when a Royal Air Force Nimrod plane exploded over Afghanistan in 2006, said it was "time for an end to military action" in Afghanistan.
"We are ill-equipped and ill-advised," he said. "We should be getting the non-militant Taliban around the table and begin talks so we can embark on a withdrawal."
Progress or quagmire?
Defense Secretary Bob Ainsworth insisted the campaign was making progress.
He said that within a year the Afghan army would take a more front-line role against the Taliban while British troops adopted "a mentoring and a training situation ... giving them the steer and the capacity and the knowledge to be able to do the job that they will need to do."
But the opposition Liberal Democrats said Britain should rethink its strategy.
Its defense spokesman, Nick Harvey, said that "nothing I have seen in this conflict leads me to believe it is even remotely possible that British troops will be off the front line within one year."
"Rather than trying to sway public opinion with false optimism, Bob Ainsworth must admit we need a fundamental change of gear, and a shift from a purely military campaign to one which focuses on achieving peace through meaningful political engagement, co-operation and progress," he said.
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