The idea of the USA and the United Kingdom at war seems ridiculous today given both countries fought as allies in two world wars, and more controversially, the 'special relationship' that has supposedly existed ever since. However, the world looked a different place after WW1, when many in the USA railed against British command of seas, which impinged on the US policy of freedom of the seas. The rights of neutral states meant little if belligerents had effective control of the seas, something that the UK regarded as essential to link together its empire and dominions. This was reflected in the various efforts to limit naval expansion after WW1.
The US war planners developed War Plan Red (they colour coded countries and the UK was red) in response to a possible UK attack from Canada and on US maritime interests, specifically sealing off the Panama Canal, using bases in the Caribbean. The plan set out various options, ranging from sealing off Canada to outright invasion and occupation. The naval options included dominating the sea lanes between the UK and Canada as well as defeating the Royal Navy in the Caribbean.
The plan documentation is very detailed and most of it is reproduced in the book, which admittedly doesn't make for easy reading. It covers the political as well as military operations. The discussion regarding Canada is particularly interesting, including the possibility that Canada might declare neutrality (Dominions had that option), and that this might be welcomed by the UK, which would avoid having to defend such an isolated ally. Naval planners regarded the seizure of Halifax in Nova Scotia as the key to control of the sea lanes and the plan includes various options for achieving this.
The plan was championed by those within the military establishment who promoted the concept of American imperialism. This tapped into the views of Far-Right groups who were larger and more influential than many realised. The book explores the various white supremacist and anti-semitic groups, their use of the radio as the new media of its day and the networks of political support in Congress. The American Dream was fine, so long as it was controlled by a small group of rich white businessmen like Ford, Rockefeller, Carnegie and JP Morgan. If this all sounds familiar today - it should!
The final third of the book takes the story to the UK at the outbreak of WW2. War Plan Red may have been shelved but that didn't mean there wasn't strident opposition to the USA joining the war from Imperialists and Isolationists. The appointment of Joseph Kennedy (father of JFK) as ambassador to the UK is covered in detail. Kennedy was strongly opposed to joining the war and, at the very least, was not unsympathetic to the Nazis.
The USA then established a large intelligence-gathering operation in London, with the agreement of the British government. This grew into much more than normal 'spying' and dealt with lend-lease, the occupation of Iceland and much more. The outputs from this work including the important Chaney Report of 1940, seem to be less about spying on the British and more learning the lessons from the war. There is nothing new in this as military observers from neutral countries were attached to armies throughout the 19th century, They provide some of our most useful sources on conflicts like the Russo-Turkish War.
War Plan Red is a fascinating story and deserves telling, including the American political context. The link to later events in the UK is possibly a bit tenuous. While it may have formed the basis for the Cold War activities of the CIA, that doesn't seem to be the focus in 1939-40.
The extensive reproduction of documents in the main text makes the book hard going in places. It might have been better to put them into appendices and pick out the key points in the text. The text is broken up by the extensive use of period photographs, and while they are interesting, they often don't have much relevance to the story being told.
War Plan Red is a great story. Importantly, it was approved at the highest level and wasn't just an academic exercise to keep military planners busy. For the wargamer, it offers a number of new scenarios for interwar armies and naval gaming in particular.