Watch part two

He is the most senior military officer in the US.

As chairman of the joint chiefs of staff under both George Bush, the former US president, and Barack Obama, the current US president, Admiral Michael Mullen sits at the strategic helm of two of the world's most ambitious and controversial wars.

As thousands of US troops descend on Afghanistan, and deadly predator drones continue to patrol the Pakistani skies, the cost of US operations against the Taliban are for the first time projected to exceed the cost of the occupation in Iraq.

So where is it all going and what exactly is the US trying to achieve with its foreign wars?

Josh Rushing goes one-on-one with Michael Mullen to find out what US military strategy looks like in the Obama era.

This episode of Fault Lines can be seen from Thursday, July 23, at the following times GMT: Thursday: 0600, 1630; Friday: 0130, 0830; Saturday: 1130, 2330; Sunday: 0630, 2030; Monday: 1430; Tuesday: 1230, 1930; Wednesday: 0300.