ABCA Armies (formally, the
American, British, Canadian, Australian and New Zealand Armies' Program) is a program aimed at optimizing interoperability and standardization of training and equipment between the armies of the
United States of America,
United Kingdom,
Canada,
Australia, and
New Zealand, plus the
United States Marine Corps and the
Royal Marines. Established in 1947 as a means to capitalize on close cooperation between the United States, United Kingdom, and Canada during
World War II, the program grew to include Australia (in 1963) and New Zealand (as an
observer from 1965, with full membership in 2006).