A year on from Barack Obama's inauguration, Simon Schama examines the issue that more than any other will determine the fate of his presidency: Afghanistan. It's a war which Obama inherited but which he has pledged to continue fighting - a conflict that will cost many more American and British lives.

As Simon Schama explains, it wasn't just a political miscalculation which landed the US and its allies in military crisis, but a historical miscalculation - a refusal to learn from the conflicts of the past. By committing America and its allies to wars in Iraq and Afghanistan, George Bush and the neocons allowed the battle against the Taliban to slide. The neocons were obsessed with World War Two, and persuaded themselves that both wars would - like the Second World War - be glorious liberations; decisive military victories.

However, as Schama discovers, it's not to World War II, but to America's forgotten war in Korea, that US policymakers should have looked if they wanted to understand the thorny reality of America's twentieth-century conflicts. The president who took America into Korea was Harry Truman. As Simon Schama explains, in Truman's handling of this bloody war, and in his statesmanship at a time of international crisis, there are profound lessons for Obama today. Show less