In 1980, the Royal Navy requested Trident I missiles under the Polaris Sales Agreement. In 1982, the agreement was changed to supply Trident II instead.
^Matthew G. McKinzie; Thomas B. Cochran; Robert S. Norris; William M. Arkin. THE U.S. NUCLEAR WAR PLAN: A TIME FOR CHANGE(PDF) (Report). Natural Resources Defense Council. p. 19. Archived(PDF) from the original on 2021-07-31. Retrieved 2021-09-01.