They have not always seen eye to eye about the future of a country that has become the most treacherous of troublespots.
But yesterday, standing side by side, Gordon Brown and Afghanistan's President, Hamid Karzai, made a remarkable job of looking like brothers-in-arms.
The performance – and the mutual applause – at a press conference in Kabul said much about the depth of the crisis that has gripped Afghanistan, as an enduring Taliban resistance threatens the country's struggling democracy.
As Mr Brown was on his way for his surprise Christmas visit, it emerged that four Royal Marines had been killed in two separate explosions in Helmand province. The four were: Sergeant John Manuel, 38, from Gateshead; Corporal Marc Birch, 26, from Northamptonshire; Marine Damian Davies, 27, from Telford; and Lance Corporal Steven Fellows, 26, from High Wycombe.
The losses brought to 132 the number of British military personnel killed in Afghanistan since the start of operations in 2001. But it was the circumstances of one of the attacks, in which Sgt Manuel, Cpl Birch and Marine Davies were killed by a 13-year-old suicide bomber pushing an explosive device hidden in a wheelbarrow, that brought the most dramatic response from Mr Brown. "For the Taliban to engage in such cowardly behaviour is something that will offend public opinion not just in Afghanistan and Britain, but right across the world," a visibly angry Prime Minister said.
Sgt Manuel, a veteran of campaigns in Iraq, Belize and Kosovo, was nearing the end of his career in the Marines, and planned to become an advanced motorcycle instructor for the police. Cpl Birch, an anti-tank specialist who gave covering fire to frontline troops, was also a keen footballer who played for his unit. Described as a devoted family man, he had recently married. Marine Davies had a young son, and his wife is expecting their second child. His commanding officer, Major Richard Maltby, described him as: "A consummate professional, dedicated to his family and friends, and the Royal Marines."
LCpl Fellows, killed on patrol when an explosion hit his vehicle, joined the Marines after a stint as a holiday rep. A rising star, he was promoted early and was described by officers as a "tough, compassionate man" who "performed faultlessly" in Helmand. His friends spoke of an intelligent, humourful colleague devoted to his wife and family.
After talks with Mr Karzai, Mr Brown confirmed a pledge to send a British civilian task force to help tackle corruption and promote good governance inthe country.
The talks came after Mr Brown had advanced closer than any other Prime Minister to the front line of the struggle against the Taliban when he visited the town of Musa Qala, recaptured from the insurgents last year.Reuse content