Over a period of 50 years, the Soviet Union (and now Russia) has developed a highly-efficient centrifuge technology and a large R&D and industrial complex to produce enriched uranium for nuclear weapons (in the past) and nuclear reactors. The enrichment complex is a crown jewel of the Russian nuclear complex and will remain significant for Russia's economy. Because of its role in the 1993 U.S.-Russian HEU agreement, global nuclear markets, and efforts to control the spread of centrifuge enrichment technology, the Russian enrichment enterprise is also of significant importance to international security.