SHOWING at Salisbury Arts Centre on Tuesday is the documentary The Unknown Known, a one-to-one conversation with former US Secretary of Defence under George W Bush, Donald Rumsfeld.

This gripping documentary sees acclaimed strategic master of interrogation Errol Morris (The Fog of War) do battle with the king of spin and stoicism under questioning.

Rumsfeld’s troubled relationship with the English language spawned several humorous books and the title of the documentary comes from one of his “enigmatic”

pronouncements: “There are known knowns.

“There are things we know that we know.

“There are known unknowns.

“That is to say, there are things that we now know we don't know.

“But there are also unknown unknowns – there are things we do not know we don't know."

Rumsfeld had an astonishing career, working for no fewer than four US presidents.

He was a principal architect of the so-called “war on terror”, sending troops into Iraq and then Afghanistan.

The film starts at 8pm and tickets cost £7.25 are available from salisburyartscentre.co.uk.