War Plan Red

War Plan Red

Joint Army and Navy Basic War Plan Red, also known as the Atlantic Strategic War Plan, was a hypothetical war plan by the United States to fight Great Britain (the "Red" forces)." Although a war plan (theoretical), it nevertheless discussed the potential for fighting a hypothetical war with Britain and its Empire and what steps would become necessary to defend the Atlantic coast. It also discussed fighting a two-front war with both Japan and the British Empire simultaneously (as envisioned in War Plan Red-Orange).

War Plan Red was developed by the United States Army following the 1927 Geneva Naval Conference and approved in May 1930 by the Secretary of War and the Secretary of Navy and updated in 1934–35. In 1939 a decision was taken that no further planning was required but that the plan be retained. War Plan Red was not declassified until 1974.

The war plan outlined those actions that would be necessary to undertake war between Britain and the United States. The plan suggested that the British would initially have the upper hand by virtue of the strength of its navy. The plan further assumed that Britain would probably use its dominion in Canada as a springboard from which to initiate a retaliatory invasion of the United States. The assumption was taken that at first Britain would fight a defensive battle against invading American forces, but that the US would eventually defeat the British by blockading the United Kingdom and economically isolating it.