A number of american pilots surveying a map.

War Plan Red: America's secret plan to invade the United Kingdom

It's hard to imagine two nations that are on better terms than the United States and the United Kingdom. Ever since the end of World War II, these countries have had a "special relationship". This has a lot to do with the course of international diplomacy, and the shared cultural and political values which make the two nations natural affiliates. But it was not always thus. It's easy to forget that at one time America and Great Britain were the bitterest of enemies during the war for independence. The British saw the rebel colonists as upstart anarchists eroding the order of their proud empire, while the loose confederation of states believed that they were ridding themselves of the oppression of King George in the name of Democracy.

Even well into the 20th century, the relationship between the states and the United Kingdom had been coloured by suspicion, mistrust and espionage. Although today, the US is the world's biggest economic, industrial and military superpower, Great Britain still controlled a staggering amount of territory overseas and had a vast amount of naval and infantry power to draw upon. In an age where competing factions and covert alliances had already led to a war which had decimated Europe and the Ottoman Empire, the prospect of a war between the United States and Great Britain was terrifying... but not completely unlikely. After all, the Great War, which consumed a generation of young men, had come about thanks to the assassination of an Austrian monarch. America's top brass had to prepare for the unthinkable. They had to strategise an invasion of the British Empire. This was America's top-secret War Plan Red.

War Plan Red was developed by top generals within the US military, outlining the steps they would have to take in the event of an invasion of the Atlantic coast by Great Britain. In the late 1920s and early 1930s, the British navy was undoubtedly the most formidable in the world. A blockade and subsequent mainland invasion of the east coast could prove devastating. The forward-thinking American generals were much like any decent football coach: they wholeheartedly believed that the best defence was a good offence, and thus believed that the best way to guarantee America's safety was to strike first and invade the empire.

Following the 1927 Geneva Naval Conference, Patrick J. Hurley and Charles Francis Adams III (secretaries of war and the navy respectively) approved the development of War Plan Red, which was later updated in 1934–35. Since only Congress holds the power to declare war in the name of the United States, the proposed scenario was never submitted. Instead, it (thankfully) remained the pipe-dream of paranoid officials until it was later declassified in 1974. Despite the fact that a conflict between the US and UK never came to pass, the details of the scheme are extremely intriguing.

A picture of the American war of Independence. Credit: Getty

For starters, the plan assumed that an invasion of Britain's mainland was not feasible, and also that Britain would probably use Canada (a part of the British Commonwealth to this day) as a springboard for their potential ground invasion. Thus, the United States would be obligated to invade Canada first in order to cut off British aid. This would also have the effect of blocking off potential food supplies to the UK, which would slowly starve the population at home and cripple the military through a lack of resources. Hurley and Adams planned to march US troops through the state of Vermont in order to quickly capture Montreal and Quebec, and simultaneously capture Winnipeg and Ontario via North Dakota.

By seizing the Great Lakes and blockading Canada’s ports, they could effectively cut off supplies to Canada, which would force the United Kingdom to rely solely on its navy and fledgeling air force. Hopefully, it was theorised, an American occupation of Canada would put extreme pressure on parliament to settle for peace. However, the United States had no intention of returning captured territory to the UK. If War Plan Red had ever come to pass, Canada would have been incorporated into the US. A 1934 document stated clearly that: "The policy will be to prepare the provinces and territories of CRIMSON (Canada) and RED (Great Britain) to become states and territories of the BLUE (American) union upon the declaration of peace."

There were many such plans developed secretly by the American military-industrial complex during the twenties, each of which were classified by colour. These plans included "War plan White" for a civil war or revolution against the incumbent administration, "War Plan Green" for a proposed invasion of Mexico and "War Plan Purple", in case of a war in Central America. One scenario (Gold) pitted the U.S. against the combined forces of France, Canada, and Britain.

American soldiers on patrol. Credit: Getty

Strangely enough, there was little development of "War Plan Black", a proposal for strategy in the event of a war against Hitler's Germany. In fact, when War Plan Black was leaked to the press in 1927, it was met with public outrage and shock. The isolationist United States wanted no part of any European conflict, unless they were invaded first. It was not until the Japanese attacked Pearl Harbour that America entered the war, and even then, a planned invasion of Germany was not considered until 1939, by which time the threat posed by the Third Reich was too dire to ignore.

On the other hand, the British Royal Navy never planned for war with the United States, although some more suspicious officers believed a conflict might arise if they attempted to regulate international trade too aggressively. It was thought that, in the event of a war, the navy could transport an army to Canada, but saw defending Canada against the US as an impossible task. Ultimately, it was believed that American and British values were similar enough that war between the two nations was unlikely, an assumption which has proven true to this very day. With the loss of Britain's empire, it now seems extremely unlikely that the UK could hold its own in a scrap with the US. But who knows what strange and inscrutable path history might have taken if things had gone the wrong way? Let's just hope that War Plan Red never gets dusted off.