The U.S. Navy has in the past cooperated with an alien race to develop technology that can be used to defend the planet against invasions from reptilian alien attacks. This is according to claims made by William Tompkins, a U.S.-based writer, in his book Selected by Extraterrestrials. Having worked for the Navy as an aircraft designer during the '50s and '60s, he apparently had access to highly classified information and bases that offered sufficient evidence of the existence of an alien race that provided technological knowledge to the human race.
He was reportedly based at the San Diego's Naval Air Station, and was during WW2 in contact with Nazi Germany's moles who worked in top secret aerospace facilities. According to the book, U.S. spies in Germany discovered that the Germans had received sufficient info on how to create antigravity aircraft, beam weapons, and more from reptilian aliens. They apparently gave him this information so he could conquer the world.
Reptilian aliens, according to the book, attack numerous planets and aim to disrupt planetary life, colonize, and enslave its inhabitants. Meanwhile, another alien race, he dubs "The Nordics," worked with the U.S. to counter their rivals' advances. His book features sketches of spacecrafts he designed. He personally came up with designs for five spaceships and dozens of support ships that were created to fend off invading lizard aliens.
They include a 2.5km Naval Spacecraft Carrier and a 1.4km Naval Spacecraft Battle Cruiser. The aforementioned ships were built decades later in the 1980s, but construction began in the '70s. According to his revelation, the project was under a highly classified program called Solar Warden. Apparently, wars with reptilian aliens were, and still are, very short-lived and The Nordics had similar ships and equipment as the ones built for the Navy. They were also involved in wars to protect our planet.William apparently worked for the Douglas Aircraft Company for 12 years and joined the company in 1951. Douglas Aircraft had been contracted by the government to undertake various projects for the Navy. It was while there that he supposedly worked with The Nordics to create antigravity aircraft. Tompkins' descriptive evidence has had conspiracy theorists citing it as additional evidence that the U.S. government has been involved in a cover-up involving the existence of aliens, as reported by the Daily Star.