War Plan RED: Lessons

[July 24, 2026] One of the timeless precepts of war is to always be prepared, especially for the unexpected. This idea is as old as warfare itself, a constant companion throughout human history. Those who fail to plan should plan on failing. America’s military has often started from a position of relative peacetime weakness, which has driven its planners to prepare exceptionally well for potential conflicts. One of the most intriguing examples is War Plan RED.

War Plan Red was a contingency plan developed during the interwar period (primarily in the late 1920s and formally approved in 1930) for a potential war with the British Empire.  It was coded as “Red,” likely referencing the Red Ensign or the iconic red coats of British soldiers. In hindsight, such a conflict would have been extraordinarily interesting, but thankfully it never materialized. Still, we can learn a great deal from the serious planning that went into it.

The plan focused heavily on invading and occupying Canada (coded as “Crimson”). American planners assumed that, in the event of war, Britain would use Canadian territory as a staging ground to launch attacks against the United States. It was one of several color-coded war plans created by the U.S. War Department and the Joint Army-Navy Board. Importantly, War Plan Red was never seriously considered for execution, received no presidential or congressional approval, and remained a routine staff exercise for preparing against worst-case scenarios.

Historical Context:

After World War I, underlying tensions simmered between the United States and Britain over war debts, naval power, trade competition, and global influence. U.S. strategists worried that Britain might leverage its dominion in Canada to threaten American security. The goal was therefore to neutralize this potential threat by securing the entire North American continent as an impregnable defensive fortress. While these assumptions may seem fantastical to modern readers, they reflected the strategic thinking and great-power rivalries of that era.

Canada was viewed as particularly vulnerable due to its long, shared border with the U.S., its relatively small independent military, and its dependence on British reinforcements across the Atlantic. The plan mirrored the era’s mindset, in which even close neighbors felt compelled to prepare for unlikely conflicts. Interestingly, Canadian planners also developed reciprocal strategies for defending against or countering a possible U.S. invasion.

Core Strategy:

The American strategy emphasized rapid preemptive strikes to seize key objectives before British forces could reinforce Canada:

Halifax, Nova Scotia: The primary target. A joint Army-Navy assault aimed to capture this vital Atlantic port and deny British naval access. Some versions of the plan reportedly considered the use of poison gas. This should not surprise students of history—during World War I, poison gas was routinely employed on the battlefield, and the United States itself had used it against German forces.

Niagara Falls Hydroelectric Plants: These were targeted to disrupt Canadian power supply and industrial capacity. For anyone following the Russia-Ukraine war or recent U.S. operations against Iranian targets, the logic is familiar: large power infrastructure holds strategic value far beyond the physical plants themselves because crippling energy production paralyzes an adversary’s war effort.

• Multi-Front Invasion:
• From Vermont: Advance on Montreal and Quebec.
• From North Dakota: Target Winnipeg and key western railheads.
• Midwest operations: Capture Ontario’s nickel mines and other critical resources.

Naval Actions: Gain control of the Great Lakes and impose blockades on Atlantic and Pacific ports. Blockades represent classic military strategy. While large-scale naval blockades are rarer today, their modern equivalents—economic sanctions and trade embargoes—serve similar purposes.

Detailed planning included specific roads, troop movements, supply logistics, and timelines. The U.S. even conducted large-scale war games involving tens of thousands of troops to test elements of these scenarios. The ultimate objective was straightforward: deny Britain any foothold in North America. This type of thorough, multi-domain planning remains relevant; one need only examine major conflicts in the 21st century to see how seizing key terrain, infrastructure, and logistics continues to shape outcomes.

War Plan Red was updated in the mid-1930s but became obsolete as common threats emerged in the lead-up to World War II. The United States, Britain, and Canada soon forged a powerful alliance that has endured for generations. The plan was declassified in 1974, generating public interest and some light diplomatic amusement rather than controversy. I personally found it fascinating during my studies at the U.S. Infantry school in 1983.

Books such as Kevin Lippert’s War Plan Red delve deeply into the topic, including reciprocal Canadian plans. The book includes maps and original documents, and it highlights the delightful irony of today’s exceptionally strong U.S.-Canada partnership. I highly recommend it—not primarily for the historical narrative (though that is captivating), but for its insights into rigorous planning processes, realistic assumptions, resource analysis, and timeless principles of military strategy.

In the end, War Plan Red was purely theoretical staff work from a different era of great-power competition. Today, the U.S.-Canada border remains the world’s longest undefended international boundary. It stands as a powerful symbol of deep alliance, reinforced through NORAD, NATO, shared democratic values, and robust economic ties.

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Please read my books:

1. “55 Rules for a Good Life,” on Amazon (link here).
2. “Our Longest Year in Iraq,” on Amazon (link here).