Dr. Abdul Qadeer Khan recently died as a national hero in Pakistan for helping his country develop its nuclear bomb in 1998 to rival India's nukes. GZERO World takes a look at A.Q. Khan, whom former CIA boss George Tenet once said was as threatening as Osama bin Laden, stole nuclear secrets from a Dutch uranium enrichment company to build centrifuges for Pakistan's atomic weapon. But he didn't stop there: in 2004 A.Q. Kahn was placed under the Pakistani version of house arrest for sharing his nuclear recipes with Iran, Libya, and North Korea. He was finally pardoned five years later, and remains as beloved by his countrymen as he is regarded elsewhere as one of the most dangerous men in history.

Watch the episode: Nuclear weapons: more dangerous than ever?