The UK Ministry of Defence and the US Department of Defense signed the UK-US Defense Trade Cooperation Treaty in 2007. Under the terms of this treaty, the UK must follow set procedures when dealing with “Defense Articles”.
“Defense Articles” means “articles, services, and related technical data, including software, in tangible or intangible form, listed on the United States Munitions List of the International Traffic in Arms Regulations, as modified or amended”.
Document
United Kingdom / United States of America Defense Trade Cooperation Treaty
PDF, 360KB, 30 pages