Is Saudi Arabia a Dangerous Ally?

The oil-rich kingdom of Saudi Arabia is one of the west's staunchest allies in the Middle East, but some now fear that is a problem, producing instability and the rise of extremism. Emily Maitlis hears from senior western leaders who criticise Saudi and want the west to pull back. We also speak to Saudi leaders themselves, who are pushing through a programme of reforms, and report on the ground to look at how free ordinary Saudis are. Plus how does North Korea make any money with the sanctions linked to its nuclear programme? Meet the western businessmen doing deals there.