"Maybe if one of my predecessors hadn’t screwed up so badly, we’d all be one army"

Today, on Independence Day, David Cameron found himself addressing US Marines at Camp Leatherneck in Afghanistan. July 4 is a bit of a tricky moment for British leaders, marking as it does a historic military and political defeat for Britain.

For Mr Cameron, whose thoughts on British history have caused him some trouble in the past, it might have been especially difficult.