Operation Long Jump was an Axis plan to assassinate Roosevelt, Stalin, and Churchill at the Teheran Conference of 1943.

Hitler approved the assassination of all three Allied leaders, assigning the mission to SS commando Otto Skorzeny to the job.

Luckily, the plot was foiled when a double agent gave away the sneak attack.

The proposed Japanese invasion of Fiji, Samoa, and New Caledonia in 1942 was named Operation FS. Had it been carried out, a blockade and attempt to force Australia’s surrender would have been inevitable.

An invasion of Australia was impractical and costly, but Japan saw Australia as a potential Allied base which would make them a threat to Japanese defenses in the South Pacific.

The disastrous Japanese naval setback at Midway made Japan change its mind about the operation. They were on the defensive in the South Pacific as a result and were never a threat to Australia again.

British and American troops made plans to invade France in the spring of 1943, and it was called Operation Round Up. The Soviets were pressuring the Allies to open a second front in Europe.

It was Dwight Eisenhower who proposed the ambitious plan, but the Allies didn’t have experienced men or the equipment for the invasion.

Operation Overlord did happen, but Allied powers waited until they were truly ready in June 1944.

The proposed US invasion of Brazil was called Plan Rubber and was meant to prevent Axis forces from using Africa to gain an advantage in the Western hemisphere.

Brazil was led by Getulio Vargas in 1941 and the idea of an invasion led him to negotiate with the Allies instead.

Operation Unthinkable was Winston Churchill’s plan. He did not trust Joseph Stalin after the war and drew up two contingency operations in 1945. The first was an offensive attack by US, British, and Polish forces at the center of Soviet lines.

Churchill’s second, more peaceful, idea was a defensive plan which remained in place throughout the Cold War. They would act only if the Soviets attacked the transfer of American troops to the Pacific.

In August 1939, Germany made a non-aggression pact with the Soviet Union and the French and British were convinced that Russian oil would fuel the Nazis. Britain and France concluded that the USSR was considered an enemy when the Soviets invaded Poland and Finland in 1939.

Operation Pike was a plan to continuously attack Soviet oil fields in the Caucuses from bases in Iran and Syria.

But Britain postponed their plans when Germany invaded France and the circumstances of the war saw no further need for such an operation.

Psychologist BF Skinner came up with Project Pigeon. This involved actual pigeons guiding a warhead by pecking on the screen to activate warheads and re-calibrate the plane’s flight path.

The National Defense Research Committee provided $25,000 in research funding, but the project was canceled in 1944 for higher strategic priorities.

The Navy revisited the idea in 1948, calling it Project Orcon, but it was canceled again in 1953. Electronic advancements negated the need for pigeons.

Hitler shifted his gaze to the strategic British outpost of Gibraltar after conquering France in 1940 and planned Operation Felix to enter Spain via the Pyrenees before launching an attack on land.

This required the agreement of Spanish dictator Francisco Franco, however, and that meant Spain would join the war as an Axis power.

But negotiations fell short as Spain was still economically vulnerable after its civil war. Franco did not want Britain taking Spanish possessions like the Canary Islands and the Azores. German officials including Hitler were unsuccessful in convincing Franco.

Hitler was obsessed with bombing New York according to Nazi Minister of Armaments and War Production Albert Speer. German designer Willy Messerschmidt was the man working on several long-range bomber prototypes to help fulfill Amerika Project.

Three prototype models were developed in April 1942. The Heinkel HE-277, Junkers JU-390, and the ME-264.

A plan to attack the US was drawn up but Germany began to focus on rocketry and weapons that were more realistic. None of the prototypes were ever used against America.

Operation Ketsugo was Japan’s defense against an Allied invasion that they saw coming. The predicted casualties were enormous as Japan planned a kamikaze assault on the Allies.

While it never happened, that’s only because of the atomic bomb attacks.

As controversial as the atomic bombs were, the US military was fully prepared to invade Japan if the bombs weren’t dropped. Operation Downfall had two components. Operations Olympic and Coronet. Olympic was intended to capture the island of Kyushu with the operation starting on November 1, 1945.

Coronet focused on capturing Tokyo. It was a larger effort using more than 50 divisions of the US military including assistance from British troops. Casualty estimates for Coronet ranged from 300,000 to 1,000,000 US servicemen, having them consider alternatives to an invasion.

Japanese casualties were estimated at 10 million based on a predicted fanatical defense in Okinawa. The country’s population, including Allied POW’s on the mainland, would be nearly wiped out.

The atomic bombs took out Hiroshima and Nagasaki, but Operation Downfall could have wiped out more of the Japanese people.

Like something out of a horror movie, the bat bomb was a four-foot-long, bomb-shaped weapon that would release hundreds of bats fitted with tiny incendiary devices over Japan. The bats would fly out over a radius of 20 to 40 miles, and with Japan’s wood-and-paper buildings, those incendiary devices would have caused chaos.

Louis Fieser, the inventor of napalm, created a tiny explosive and using the Mexican Free-Tailed Bat. Testing the device resulted in an accidental fire at an Air Force airbase in Carlsbad, NM. The research on the atomic bomb put a stop to the plans of the bat bomb and other more unrealistic systems.

British inventor Geoffrey Pyke proposed the idea of a floating island as large as an aircraft carrier to be constructed in the Atlantic Ocean. Project Habakkuk would be an island that served as a refueling location for planes that took out German U-Boats.

Naturally, icebergs were unstable and could shatter with the use of explosives. So Pyke invented a new substance from ice and wood pulp which he called “Pykrete.” It could be manipulated like wood.

Lord Mountbatten and Winston Churchill were interested, and a small block of pykrete was commissioned to be constructed in Lake Louise, Alberta as a test. It weighed 1,000 tons, so the cost of a full-scale version is what eventually doomed it.

Adolf Hitler disliked Switzerland so much that the Wehrmacht began preparations for an invasion after France surrendered. Plans were made and revised but Hitler never gave the order for Operation Tannenbaum.

The Swiss gave Germany many perks which could have been a reason for Hitler never giving the command.

Hitler, for all his animosity towards Switzerland, understood that an invasion and a two-front war made a Swiss invasion an impossibility.

The Nazis wanted to flood Britain with hundreds of millions of counterfeit pound notes. Operation Bernhard was orchestrated by SS Major Bernhard Kruger who recruited Jewish prisoners with printing and engraving skills and set them up in a top-secret printing operation in the Sachsenhausen concentration camp.

During the war, Operation Bernhard forged over a million pounds in banknotes. The Germans didn’t have enough to affect Britain’s economy, but they did use it to pay spies and transactions with foreign governments, such as Italy. The Turkish spy Elyesa Bazna, aka Cicero, tried to sue the German government for fraudulent payments but was unsuccessful.

The counterfeit currency was dumped into Austria’s Lake Toplitz after the war. They were discovered in 1959 and yet fake British pounds still showed up in Britain, forcing the government to redesign all currency that had a value of five pounds or more.