Mike Gravel is a former senator from Alaska who ran for president this year – twice – once as a Democrat and once as a Libertarian.
In his campaigns, he has criticised the military-industrial complex that shapes US policy and fought for "direct democracy" – allowing ballot initiatives at the federal level so people can decide laws without Congress.
Gravel is a leading critic of the Iraq war and all pre-emptive wars, including war with Iran. He joins Riz on Wednesday.
This episode of Riz Khan airs on Wednesday, September 17, 2008, watch live at 2030GMT, with repeats at 0030GMT and 0530GMT.