Bout is a Russian who was the world's most notorious arms dealer in the 1990s and early 2000s. He was serving a 25-year prison sentence in Illinois before being freed as part of a U.S.-Russia swap.
The decision effectively sends Griner to serve out her nine-year term in a Russian prison colony, even as the U.S. and Russia appear set to reengage in talks for a possible prisoner swap.
The U.S. and Russia are trying to work out a prisoner exchange that involves basketball star Brittney Griner. While they've done deals for decades, the trading usually involves spies for spies.