America’s technological advantage has always been a part of its successes on the battlefield. Military research bureaus and DARPA spend every minute of every day trying to make sure the United States stays ahead of the technological arms race.

But, without Britain, America might have lost this arms race a few times. During World War II, Britain handed over many of its more advanced technologies in the hope that American companies would produce more copies for use against Hitler. After the war, the British threw away some extra bones as ceramic armor for the tanks.

Here are 5 military technologies America relies on that were designed “across the pond”:

1. Proximity fuses

Proximity fuses use Doppler radar or other sensors to determine when a weapon is within a certain distance of its target or the surface. The weapon then explodes. It makes artillery and tank shells more effective against infantry and allows more sophisticated weapons to be used for anti-tank, anti-aircraft and anti-ship missions.

American researchers received British designs and found out how to make fuses more robust. The improved and top-secret detonators were sent to the frontline forces with strict instructions to use them only when the enemy would be unable to find unexploded shells. The shells proved their worth in the battles of Guadalcanal and the Battle of the Bulge.

2. Jet engines

Lockheed Martin launched the military’s first jet aircraft before Pearl Harbor, but the military rejected it. Lockheed Martin continued to work on its version of the design, but America still got its first jet fighter from Britain. US Army Air Chief General HH Arnold was visiting facilities in Britain when he was shown the first British jet fighter, the Gloster Meteor, which was undergoing its final tests.

He asked for engine designs to be sent to America and they were. A working copy of the engine and the inventor, Royal Air Force Officer Frank Whittle, followed and helped General Electric develop the jet engines for the future P-59 fighter jet. Lockheed Martin, who was kept in the dark, then created the F-80 from its own research on the jets.

3. Radar

A single copy of the cavity magnetron, a device capable of creating short microwaves, was sent to MIT in 1940 after it was delivered by British scientists during the Tizard mission. Overnight, it changed America’s understanding of radar. American researchers had found themselves in a bind because they could not find a way to produce sufficiently short waves of energy.

The magnetron was the breakthrough they were looking for, and MIT built the Radiation Lab to study the device and build new radar systems with the design. The new radar systems allowed planes to track German submarines in the Atlantic, saving Allied convoys and allowing the United States to deliver men and equipment to the European theater.

4. Nuclear technology

That’s right. The most powerful weapons in the United States were made with the help of Great Britain. Nuclear fission was discovered in 1939 and British and American scientists recognized the possibility of a uranium bomb. But American scientists working before and during the war initially believed that isolating the necessary isotopes would either be impossible or incredibly expensive.

The Maud committee in England disagreed and sent their research to America. After high-level meetings between national leaders, Britain and America agreed to work with Canada to create the bombs. Britain had science, Canada had uranium, and America had machines and money.

5. Chobham’s armor

When the military was deciding how the XM-1 tank would protect itself against Soviet missiles and anti-tank shells, the British offered the United States their Chobham armor, a sandwich of steel and other metals that disrupt the movement of a projectile attempting to pierce. this.

A modified version of the Chobham armor was selected for what would become the M1 Abrams Main Battle Tank. Chobham armor was also used in the British Challenger tank. Both armies were able to prove the wisdom of ceramic armor in Desert Storm when the Abrams and Challenger tanks were able to dodge dozens of RPG hits and Iraqi tank guns.