The increasing war toll has complicated the political calculus in Britain, as has the reluctance of other European NATO members, including France and Germany, to make comparable increases in their troop commitments or to accept more of the combat risks in Afghanistan, an issue Mr. Miliband also addressed, if obliquely, in Brussels.  “People in Britain know why we all committed to this mission,” he said. “They want to know that all the members of our alliance are ready to give it the priority and the commitment it deserves. Burden-sharing is a founding principle of the alliance, the solidarity on which it is built. It needs to be honored in practice, as well as in theory.”  Underscoring the Brown government’s concern to quell public alarm at the recent deaths among soldiers, Mr. Miliband’s speech, which is available on the Foreign Ministry’s Web site, was accompanied by a Defense Ministry announcement of an end to the militarily costly “first phase” of the British offensive in Helmand Province that has led to most of the British casualties. The ministry said the emphasis was shifting to holding the cleared area, and ensuring the Taliban did not return.  The British operational commander, Brig. Tim Radford, said in a video link to London that the operation had been a success, killing, capturing or driving away most of the 500 Taliban fighters who had held an area about the size of Britain’s Isle of Wight along the banks of the Helmand River. “We had a significant impact on the Taliban in this area,” Brigadier Radford said.  In a separate statement, Mr. Brown said the Helmand offensive had started to break the “chain of terror” linking Afghanistan and parts of Pakistan to Britain. That rationale for Britain’s military role in Afghanistan was restated forcefully in Brussels by Mr. Miliband, who said that Britain, aiming to deny Afghanistan as a haven for terrorists, planned on completing its mission.  “Our enemies should never doubt our determination to accomplish this mission, because we know the very high cost of failure,” he said.  But the timing of the speech appeared, more than anything, to be aimed at shoring up support for the war in the face of rising public concern about the spike in British deaths, part of a wider toll in Afghanistan in July in which at least 69 allied soldiers, including 32 Americans, have been killed. That number includes the deaths of two British soldiers on Monday, bringing Britain’s monthly toll to its highest point since the war’s start in 2001.  Commentators in Britain, which has the second-largest military contingent in Afghanistan, have questioned whether the war can be won, and how long it can be sustained in the face of popular alarm. Mr. Miliband’s answer, in part, was that success will depend on a new political sensibility that treats the Taliban not as a militarily and ideologically coherent force but as “a wide but shallow coalition of convenience” that relies on cooperation between groups that is “opportunistic rather than strategic.”  Calling for “an effective grass-roots initiative to offer an alternative to fight or flight” for Taliban militants, Mr. Miliband described them as a motley alliance of “foot soldiers whom the Taliban pay $10 a day,” poppy farmers, narco-traffickers, warlords and “ordinary Afghans.” He said they dreaded the Taliban’s return but worried about the state’s ability to protect them. “They may not give active support,” he said. “But they acquiesce or turn a blind eye.”  Mr. Miliband offered few specific suggestions as to how allied forces could encourage defections. Instead, he concentrated on initiatives by Afghanistan to strip away corrupt local governments, create more economic opportunity and persuade citizens that they will be protected from a Taliban revival once coalition forces withdraw. “It is only when the cooperation, passive and active, of ordinary Afghans is removed that the insurgency will be fatally undermined,” he said. “The squeeze on the Taliban must come from within as well as without.”  A version of this article appears in print on , on Page A3 of the New York edition with the headline: A Weary Britain Seeks Political Ways to Defeat Taliban. Order Reprints| Today's Paper|Subscribe
Foreign Secretary David Miliband urged a new effort to persuade elements of the Taliban to enter normal politics.