War Plan Red: The secret US plan for war with Britain via Canada

Why did the US have a plan for war with Britain?

It was, and still is, normal practice for militaries to prepare for all manner of scenarios, even against allies. War Plan Red was just one of many contingencies drawn up by the US, all of which were designated a different colour.

Green covered the eventualities of a war with Mexico; Brown for an uprising in the US-controlled Philippines; Yellow for China; and Orange for Japan. White, meanwhile, focused on a domestic situation within the US.

War Plan Red (a reference to the British redcoats of the American War of Independence) was further subdivided, depending on where in the world a potential war might break out. Ruby referred to India, Scarlet was Australia, and Garnet was New Zealand. The chief anticipated theatre for any conflict between the US and the British empire, however, was Crimson: Canada.

What reason would the US have to go to war with Britain?

In the First World War, the British, Americans and Canadians had been allies, but in the years after the armistice tensions began to rise. The British Deputy Chief of Naval Staff, Vice-Admiral Sir Osmond Brock described the possibility of war as “very improbable” without going so far as declaring it “impossible”.

Since Germany had been knocked out as a naval power, Britain and the US stood alone as the global superpowers of the seas, which raised the risk of a situation somewhere in the Atlantic that could all-too easily escalate.

War Plan Red was subdivided, depending on where in the world a potential war might break out. The chief anticipated theatre for any conflict between the US and the British empire was Crimson: Canada

The most likely scenario that might lead to a naval clash was if Britain went to war with another country while the US continued to trade with it. The British would try and stop any ships believed to be heading to its enemy, but if they were American ships, possibly with an armed convoy, this risked provocation and an outbreak of hostilities.

What’s more, the colossal war debt that Britain owed the US had fuelled increasing frustrations on both sides.

How was War Plan Red going to work?

Approved in 1930, War Plan Red did not propose a direct attack on Britain, especially not its superior navy, but an invasion of Canada. The US (always designated as ‘Blue’) would shore up North America as a defensive fortress and so prevent Britain from gaining a foothold for their own invasion south of the border.

Crucial to the success of War Plan Red would be capturing the port of Halifax, in Nova Scotia, as this provided a strategically vital base for British ships. So important was this target that the plan even proposed the use of poison gas to secure it. The hydroelectric plants at Niagara Falls had to be seized too so that the Canadian power grid could be disabled.

Simultaneous assaults on the cities of Montreal, Quebec City, Toronto, Winnipeg and Vancouver would ensure the US had control of Canada’s industrial centres and railroads. From this position of strength, the Americans hoped to force the British into a quick peace deal.

What happened to War Plan Red?

During the 1930s, War Plan Red was updated a number of times. The manoeuvres were laid out in such detail that specific roads were suggested for particular American forces. The US also carried out a huge set of war games involving 36,000 troops.

But, of course, nothing came of it: the US, Britain and Canada remained allies and would once again fight on the same side with the outbreak of the Second World War.

Canada's plan for war against the US

While Britain did not have an official strategy for war against the US (or at least, one we know about), the Canadians commissioned their own secret plan 10 years before War Plan Red for an invasion of the US.

Defence Scheme No. 1, as it was called, had been headed by the Canadian director of military operations and intelligence, the war hero James ‘Buster’ Brown. It involved ‘flying columns’ of Canadian troops invading across the entire stretch of the border, occupying cities like Seattle, Spokane and Portland in the west; Great Falls, Fargo and Minneapolis in the centre; and Detroit, Niagara and Albany to the east.

Crucial to the success of War Plan Red would be capturing the port of Halifax, in Nova Scotia, as this provided a strategically vital base for British ships. So important was this target that the plan even proposed the use of poison gas to secure it

The purpose of the invasion would be to throw the Americans off guard and take control of some of the infrastructure in the northern US, before waiting for British reinforcements. This utterly relied on Britain coming to Canada’s aid, something of which there was no guarantee. If anything, it appears Britain would have let Canada fall, focusing its efforts elsewhere.

Canada, as a colony of the British empire, and the US were foes in the American Revolutionary War and the War of 1812. The rest of the 19th century had seen a number of petty border disputes, which had threatened to spill over into all-out conflict.

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The Pork and Beans War of 1838-39, began when lumberjacks from New Brunswick to the north and Maine to the south argued over which trees they could cut down. Taking its name from the lumberjacks’ meal of choice, the situation escalated until militias from both sides had mobilised on the border and US Congress authorised a force of 50,000 troops to settle the matter.

Then there was the Pig War of 1859, which saw thousands of troops and several warships mustered after a Canadian pig was shot after getting into an American garden in the San Juan Islands of the western coast. Thankfully British rear admiral Robert L Baynes did not take action, declaring he would not start a conflict “over a squabble about a pig”. It ended bloodlessly, except for the pig.