The Regional Security System (RSS) is an international agreement for the defence and security of the eastern Caribbean region. The Regional Security System was created in 1982 to counter threats to the stability of the region in the late 1970s and early 1980s. On 29 October four members of the Organisation of Eastern Caribbean States—namely, Antigua and Barbuda, Dominica, St. Lucia, and St. Vincent and the Grenadines—signed a memorandum of understanding (MOU) with Barbados to provide for "mutual assistance on request".