But he added: “Except there were maybe five that contributed. It was actually closer to one or two that by the end were actually involved in kinetic operations. In fact the patch ISAF, we joked it meant ‘I Saw Americans Fighting’.”

All of NATO’s then-28 members participated in the U.S.-led war in Afghanistan, after the alliance invoked Article 5 of the North Atlantic Treaty – NATO’s collective defense clause – on September 12, 2001, a day after the terrorist attacks that took place on 9/11.

It remains the only time the article has been invoked in alliance history.

Asked about his comments Monday, U.K. Prime Minister Andy Burnham’s official spokesperson pointed out that “thousands of British and allied families made huge sacrifices to play their significant part in that war and uphold our values,” while “more than 450 British personnel never returned.”

“Their sacrifice and that of other NATO forces was made in the service of collective security and in response to an attack on our ally,” he continued.

“We are incredibly proud of our armed forces, and their service and sacrifice will never be forgotten. And it is wrong to diminish their role.”