Watch part two
Anand Naidoo sits in for Riz Khan this week.
Chuck Hagel, the former US senator, is working on an ambitious global agenda: eliminating the entire world's nuclear arsenal.
He has joined a small but influential group called Global Zero, which includes British entrepreneur Sir Richard Branson, Jordan's Queen Noor, and a list of former US and British military and civilian leaders who are demanding that nukes be eliminated over the next 25 years.
He is a Republican, but many liberals consider him a hero for breaking with his party's ranks. When in office, he was one of the most vocal critics of the Iraq war. And when Dick Cheney, the former US vice president, recently claimed that Barack Obama, the US president, was making Americans "less safe," he lashed back, calling Cheney's claims "ridiculous".
Since leaving the senate after two terms, as he promised, Hagel has assumed the leadership of the Atlantic Council of the United States, and remains one of America's leading foreign policy thinkers. His latest book is, America: Our Next Chapter: Tough Questions, Straight Answers.
On Tuesday, Hagel gives his assessment of America's relations with the rest of the world under the Obama administration.
This episode of Riz Khan aired on Tuesday, March 31, 2009.