Who is Viktor Bout, the arms dealer who could be swapped for Griner?

FILE PHOTO: Alleged arms smuggler Viktor Bout from Russia is escorted by a member of the special police unit as he arrives at a criminal court in Bangkok October 4, 2010. Thailand's criminal court held a hearing today on a second case lodged against Bout. REUTERS/Damir Sagolj/File Photo

LONDON (Reuters) - The life of Viktor Bout reads like a spy thriller.

Russia wants the jailed arms dealer back in Moscow and is discussing a prisoner swap with the United States that could see him exchanged for Americans imprisoned in Russia including basketball star Brittney Griner.