Walt Kelly called it "New Clear PhyFizzics", then noted it was not so new, not so clear, and, when the book was dropped in a bucket of water, 'nary a fizz.'
In 1945, the US announced that they had the world's greatest weapon: U235! Of course, everything was Top Secret, so no details, but everyone knew that no other nation could possibly produce such a weapon, only the US, so when the USSR produced one after four years, the US executed the two Jewish spies who gave away the secret. The way the spies were discovered was that the Great J. Edgar Hoover picked up some people and said, 'You will be charged with espionage. If you do not confess, you will be executed. If you confess and name your accomplices, you'll get your sentence reduced to just a few years in Federal Prison. Now name your accomplices!' And the people arrested kept naming accomplices and naming accomplices until a Jewish couple, Ethel and Julius Rosenberg, said they had not been spies, they had not stolen nuclear secrets and sold them to the Soviets, and they had had no accomplices, so they were both executed (the others arrested got prison sentences of a few years, then they were released as disgraced spies who had helped the Rosenbergs give the USSR the secret to the nuclear bomb; J. Edgar Hoover said he kept waiting for a phone call on the night of execution saying the Rosenbergs were ready to confess and name their accomplices, and he would have immediately ordered their sentence commuted).
I saw a Disney comic book back in the late '50s, showing U235: the most powerful explosive in the world. He threw a speck into the Grand Canyon. Nothing happened, so they asked, 'What's happening?' and Ludwig said, 'It hasn't hit bottom yet.'
When the U235 finally hit bottom, the explosion filled the entire Grand Canyon. Nothing about radiation poisoning, though, since this was a children's comic book explanation about the atomic bomb and U235, no details like radiation poisoning allowed.
In fact, the story started that all the bombs were U235, then that one bomb was actually plutonium, not uranium, then two bombs were plutonium, and now most figure all three of the US bombs, the one tested at White Sands New Mexico, and the two dropped on Japan, were all plutonium bombs.
The grimy details finally came out about the secret facility in Chicago (the Chicago Pile) where about 50 tonnes of uranium and yellowcake were allowed to sit until a fission reaction started, then it was stopped and the Pile was moved to a more secure location. After three years of fission, the pile produced enough plutonium to make three bombs. Of course, the fact that the bombs were Plutonium was tippity-top secret, classified TS/SCI/NOFORN/BBR!!! The US wanted everyone to try to make a bomb out of U235.
Everyone knew the US was buying uranium, millions of dollars worth, but the war left most nations without millions to spend on uranium when no one thought it would work until they saw the US do it, after which, every country that has 50 tonnes of metallic uranium and wants a bomb has a bomb. The countries without bombs either don't want them, so they sell their uranium oar, or they don't have enough uranium to build a bomb.
So the Soviets didn't need any spies, nor did the French, Chinese, Indians, Pakistanis, or North Koreans (the British and Israelis didn't need any spies because they got by with a little help from their friends).
But Israel and the US want rid of Iran, and saying they are building a nuclear bomb and are only a few days away from completing one (and have been just a few days away for more than 30 years) is more than enough justification to totally destroy the country (and then return all the oil that the Iranians have been stealing since 1980 back to the rightful owners, BP).
The only teeny problem that intrudes into this brilliant and facile plan by the US and Israel is that the evil Russians and Chinese might have been helping Iran with their defences (all deny that, since if Iran lose, Russia and the PRC don't want any of the blame, and if Iran win, they want the US to know they lost to a small country with only the most primitive defences, spears and arrows and such like against the most advanced weapons in the entire world that only the US Defence Industry can produce: one can hardly believe the $trillions needed for all the advanced development by ChatGPT required to produce those US weapons).