Strategists say the first casualty of war is the plan. In a few cases, the plan never reached the war stage. And if these 10 invasions happened, the world would be a dramatically different place.


1. War Plan Red: The U.S. Invasion of Canada

In the post-WWI era, fresh from battlefield victory in Europe, the United States was building its military to compete with those of the other world powers. It was a time of global imperialism, when the aspirations of any country could end up sparking a war anywhere, with anyone. To this end, the U.S. drew up a series of "Rainbow War Plans," filled with possible war scenarios that were coded by color. The first on the list was War Plan Red: The U.S. War with Britain.

Related: These were America's colorful plans for war with the rest of the world >

In the age of the "Special Relationship" the U.S. enjoys with the UK, we tend to forget Anglo-American relations haven't always been this close. Before the rise of the Soviet Union, the U.S.' "special relationship" was more akin to its relations with Russia. Catherine the Great traded directly with the American Colonies despite the British ban on such trading and Russian ships traded with the colonies during the Revolution. The Russians kept other European powers out of the American Civil War.

War Plan Red did not involve any U.S. vs. UK action outside the Western Hemisphere. The authors believed capturing Canada would make Britain sue for peace. The first step would be an American invasion of Nova Scotia and New Brunswick, followed by a move West into Quebec. Once the Province of Quebec falls, the Canadians would have been unable to move men and supplies in either direction. This would have been followed by thrusts to capture the Great Lakes area (which is also the Canadian industrial center) to prevent attacks on the American industrial centers in the Rust Belt regions. An attack from Grand Forks, North Dakota would capture the Canadian Central Rail system in Winnipeg, and a joint blockade an amphibious invasion was called to capture British Columbia in the West.

2. The Canadian Invasion of The United States

As if the Canadians knew something was up down south, they had an invasion scheme of their own. Literally called Defence Scheme No. 1, it called for immediate action as soon as evidence of an American invasion was uncovered. The Canadians believed the U.S. would strike Montreal and the Great Lakes regions first, then Westward into the prairies and into British Columbia.

This is what it looks like to me.

In 1930, Canadian intelligence developed its counter plan. It was designed to buy time for Canadians to mobilize for war and to receive help from Great Britain. Units designed for speed of movement would capture major cities in Washington State as others in the East would capture cities in Minnesota and the Great Plains States. French Canadian forces would move to capture Albany, New York while an amphibious assault would land in Maine. As the Americans began to push the Canadians out, the retreating troops would destroy food and infrastructure as they went.

The Royal Navy at the time considered Canada to be indefensible and would not have sent a large force to help... but the Canadians didn't know that at the time.

3. Operation Downfall: The U.S. Invasion of Japan

Operation Downfall was the codename for the Allied invasion of Japan at the end of World War II. Japan surrendered after the United States dropped two atomic bombs and the Soviet Union entered the Pacific War, handily defeating Japanese forces on the Chinese mainland. Downfall would have been the largest amphibious operation in world history, a landing even bigger than the ones at Normandy the previous year.

The invasion was divided into two parts, Operations Olympic and Coronet. Olympic was the capture of the southern portion of the Japanese main island of Kyushu. Coronet used assets captured in Olympic to invade the main island of Honshu in the plains areas near Tokyo. The plan called for five million American troops with an additional one million British and Commonwealth forces. The Japanese are estimated to have mustered 35 million regular, reserve, and conscripted troops.

U.S. Troops of the 185th Inf., 40th Div., take cover behind advancing tanks while moving up on Japanese positions on Panay Island (Library of Congress)

The Japanese correctly predicted the U.S. war plan and their defensive operation plan was an all-out defense of Kyushu with little left for defenses anywhere else. A study conducted for the War Department at the time estimated at least 1.7 million American casualties because the study assumed Japanese civilians would join in the island's defense.

4. The Soviet Invasion of Western Europe

The Eastern Bloc countries maintained a defensive posture for much of the Cold War. None of the Soviets' war plans called for nuclear weapons until after Joseph Stalin's 1953 death. It was after 1953 that the nuclear tensions began to ratchet up on the continent. NATO countries had their own individual plans for nuclear war, as well. The UK alone planned to drop at least 40 nuclear weapons on Eastern Europe. The American Single Integrated Operation Plan, first created in 1960, called for raining thousands of nuclear strikes on Communist countries, even if they weren't at war with the U.S. For the West, the destruction would be so absolute, it didn't matter what came after. For the Russians and their allies, the war didn't stop at the nuclear exchange. Nukes only shaped the conventional battlefield.

Ethnic-Chechen Spetsnaz soldiers of Sulim Yamadayev's Battalion Vostok in Georgia in 2008 (Russian Defence Ministry photo)

After the exchanges, Eastern armies were to pour West, capturing cities in West Germany and pushing all the way to France. Czechoslovak armies took the middle of Europe, through to the Pyrenees while Polish and Soviet armies took the Northern parts. They planned a five-to-one advantage in troop strength and hoped to be at the Atlantic Coast within 14 days.

5. Sino-Soviet War

This one was actually a "border conflict" between the two Communist countries that almost turned into a nuclear conflict. It started over a small island on the Ussuri River, 3/4 of a mile in area. The river is the border between Russia and the People's Republic of China. In 1964, Soviet leader Nikita Khrushchev ceded the island to China but rescinded the recognition after Chairman Mao threatened to claim other Russian areas for China. By 1968, the Red Army was massed on the border.

"Shrimp on the Barbie" now called "Steak on the Barbie" by imperial decree

One of the explorers, Francois Peron, authored a confidential report for Napoleon that outlined what they saw as English encroachments on the territory, accusing the English of land grabs. He believed the French could use the land more effectively and Peron began to feed military and political information back to France.  Baudin himself may even have had a role in developing the invasion information, allegedly preparing a report on how to invade Sydney Cove. They believed 1,800 French troops back by Irish soldiers and convicts could topple British control of the entire area.