The US' Ghost Army Took Military Deception to a New Level in WWII
On Sunday, September 11, 2021, the New York Times reported on the death of a 106-year-old retired architect named Gilbert Seltzer who had died a month earlier, on August 14th. While reaching 106 might be notable in and of itself, Gilbert Seltzer was noteworthy for another reason: during World War II, he had been part of the "Ghost Army".
The Ghost Army

Officially known as the 23rd Headquarters Special Troops, the Ghost Army was first activated on January 20, 1944. Made up of 82 officers and 1,023 enlisted men under the command of Colonel Harry Reeder, it was the first mobile, multimedia, tactical deception unit in the U.S. Army.
The 23rd was comprised of engineers, architects, artists, illustrators, and photographers, including such notable figures as the fashion designer Bill Blass, the painter Ellsworth Kelly, and photographer Art Kane. The 23rd also included many graduates of both the Army's military academy, West Point, and specialized training programs. Members of the 23rd were said to have the highest IQs of any of the Army's military units.
In May 1944, the 23rd arrived in England shortly before D-Day, which occured on June 6, 1944, and were stationed near Stratford upon Avon. The unit's first task was to participate in Operation Fortitude, which was the British-designed deception that the Allied landing in Europe would take place at Pas-de-Calais rather than at Normandy.

Following D-Day, the Ghost Army simulated fake Mulberry harbors which were floating artificial harbors at Normandy at night, in order to draw German artillery fire away from where the real landings were happening. Next, the 23rd traveled to Brest, France where they convinced the German defenders of that city that a much larger force encircled the town than actually existed. To do that, the 23rd created inflatable tanks, cannons, jeeps, trucks, and airplanes which could be quickly inflated using air compressors. The decoys were slightly imperfectly camouflaged so that they would show up on enemy aerial reconnaissance, then mixed in with real artillery to make them harder to spot.
Throughout the remainder of the war, the 23rd also created dummy airfields, motor pools, artillery batteries, tank formations, and troop bivouacs that even included fake laundry hanging on clotheslines. One of the 23rd's most important operations occurred in early March 1945 and involved getting Allied troops across the Rhine River and into Germany's Ruhr valley, which was the industrial heart of the nation. Pivotal to that campaign was the capture of the Ludendorff Bridge, often called the Bridge at Remagen, which spanned the River Rhine at the town of Remagen.
The Ghost Army set up at a decoy location 10 miles south of the actual spot where two American Ninth Army divisions would actually cross the river. They deployed inflated tanks, cannons, airplanes, and trucks, while at the same time sending false radio messages concerning American troop movements. The 23rd even broadcast the recorded sounds of hammering and sawing which would be occurring if pontoon boats were actually being built.
The Ninth Army ended up crossing the Rhine almost without resistance, while the 23rd's position received heavy fire.
Military deception
As 6th century BCE Chinese writer Sun Tzu wrote, "All warfare is based on deception." Military deception includes misdirection, stealth, and subterfuge. It aims to hide an army's strengths while at the same time hiding its weaknesses, and seeks to obscure any intentions and keep an enemy guessing, so they are forced to make preparations that waste their resources.
Modern military deception came into its own during WWI when the advent of aerial reconnaissance created the need for camouflage. Not short of artists in its ranks, in September 1914, the French army founded the Section de Camouflage which pioneered the use of mesh interwoven with painted canvas to conceal gun placements. The unit also created realistic-looking trees that contained observation posts.

When America entered WWI in 1917, General John Pershing created an American version of the French camouflage unit. But, it was during WWII that military deception really came into its own. Every American soldier received training in the art of deception, and military trucks, tanks, and artillery were camouflaged with paint specific to the terrain in which they would be operating, the climate, and the season.

In forested regions, they were painted in greens and browns, while in desert terrain they were painted in tans and browns. In alpine and snowy terrain, both sides clad their soldiers in solid white fatigues, while tree branches or hay were commonly affixed to both tanks and equipment.

Gun placements in pillboxes and bunkers were camouflaged with natural foliage to avoid detection from the air. Allied forces camouflaged over 600 airports with both paint and artificial greenery, while anti-aircraft guns were hidden beneath fake farmhouses that could be moved away at a moment's notice. Anti-aircraft guns were hidden beneath fake barn roofs, under tennis courts, and beneath fake haystacks.

Since aircraft were so vital to the war effort, the British moved many of their planes away from airfields and parked them instead among the greenery on rural British farms.
Camouflage wasn't the only military deception employed, sound effects were also used. A team from the 23rd, along with engineers from Bell Labs, recorded the sounds made by armored and infantry units onto records and wire recorders, which they brought along to Europe.

Those sounds were broadcast using powerful amplifiers and speakers that were mounted on half-track trucks, making the sounds audible up to 15 miles (24 km) away. Indeed, Gilbert Seltzer described one sound operation saying, "We would move into the woods in the middle of the night, going through France, Belgium, and Germany, and turn on the sound so it sounded like tanks were moving on the roads."
So convincing were the sounds that Seltzer told an interviewer, "The natives would say to each other, 'Did you see the tanks moving through town last night?' They thought they were seeing them, ... imagination is unbelievable."

Military decoys are meant to attract attention, and the dummy heads of soldiers were created in order to attract sniper fire, which would then reveal the position of the sniper. Decoys were used to great effect in Egypt at the outbreak of WWII when there were only 36,000 British troops in North Africa, while Italian troops numbered around 250,000.
In December 1940, a team of British Royal Engineers produced 80 wood and canvas dummy tanks which were placed behind real tanks at the front at Sidi Barrani, in the Western Desert Campaign, to make their numbers look larger. The ruse worked and the British marked their first victory in the war, taking 39,000 Italian prisoners of war.
By 1944, the wood and canvas used in decoys and dummies were replaced by inflatables which were both lightweight and portable. Most importantly, they cast convincing shadows when viewed from the air.

Dummy landing craft and blowup sailors made landfall on beaches, while probably the strangest, and also some of the most effective, decoys were dummy paratroops. Only two feet tall, when viewed against the sky they appeared to be real paratroopers. They carried real firecrackers so that when they hit the ground the firecrackers exploded, confirming to the enemy that they were real.

For ships at sea, hiding something as large as a naval destroyer is hard, but Allied navies hit upon a technique called "dazzle painting". It involved painting ships in irregular patterns of sloping lines, stripes, and curves in contrasting colors. In theory, this made it harder for the enemy to ascertain a ship's course and speed.

Taking a page out of pirates' playbooks, ships also sometimes flew false flags, and navies also disguised their destroyers as hospital ships. This had the unfortunate consequence that often real hospital ships were attacked. A member of the Royal Engineers, British stage magician Jasper Maskelyne, created small-scale ship decoys out of balsa wood and canvas that looked real from the air.

Operation Mincemeat
Perhaps the most famous example of military deception used during WWII is Operation Mincemeat. Its story has been told many times, including the 1956 movie, The Man Who Never Was. To accomplish this mission, members of British Military Intelligence went to an English morgue and acquired the body of a man who had recently died. They gave the man a fictitious name, Major William Martin, and stuffed the pockets of his uniform with a military identity card, theater tickets, a picture of a girlfriend, and a letter from a banker informing him that his account was overdrawn.

To "Martin's" wrist, they chained a briefcase that contained plans for the Allied invasion of Greece and the Balkans. The body was then loaded onto a submarine which dropped it into the sea off the coast of Spain. The British then sent out a radio message saying that one of their aircraft had gone down off the Spanish coast.
While Spain was neutral during WWII, it was friendly with Germany, so that when the body washed up on shore, German spies in the country photographed the documents before sending them on to the German High Command in Berlin. The Spanish then released the body to the British ambassador who was totally ignorant of the plot. Once he radioed the British command that Major Martin's body had been found, he was bombarded with "frantic" messages from the British asking what had become of the briefcase.
On May 12, 1943, the Germans suddenly withdrew their troops from Sicily and moved them to Greece and the Balkans. On July 10, 1943, with only two German divisions left to oppose them, the Allies successfully landed in Sicily.
The aftermath of the Ghost Army
After WWII, all records concerning the 23rd were classified, members of the unit were sworn to secrecy, and the equipment created by the unit was packed away in a location that we imagine resembles the last scene in the movie, Raiders of the Lost Ark. Further information about the 23rd remained classified until 1996.
Following the war, Gilbert Seltzer returned to architecture, and among other buildings, he designed the East Coast Memorial in Battery Park, which honors soldiers, sailors, Marines, Coast Guardsmen, merchant mariners, and airmen who died in battle in the Atlantic during World War II.
From March 5, 2020, to January 31, 2021, the National WWII Museum in New Orleans held a special exhibit of artifacts created by the Ghost Army, such as the inflatable tanks.
This year, legislation to award the Ghost Army the Congressional Gold Medal passed in the U.S. House of Representatives and it is pending in the Senate. According to the New York Times article, only nine soldiers who served in the Ghost Army are still alive.