A large nuclear mushroom cloud in the sky in no more than six months? Where the nuclear bomb will be dropped?

Tadić, a nuclear physicist and member of the scientific-technical committee of "Euratome," spoke on the program Večernji TV about the future moves of the Russian and U.S. presidents regarding nuclear weapons testing.

He reminded viewers that Trump had announced the U.S. would return to nuclear testing, to which the Russian leader responded immediately that Russia would also resume nuclear tests.

“I am quite saddened by this because the world is essentially going back thirty years. The last nuclear test was conducted in 1992. Since then, there have been none. Moreover, in 1996, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was signed. This treaty was signed by the U.S., Russia, China, and other major powers,” Tadić emphasized.

However, the U.S., Russia, China, Egypt, Israel, Iran, India, Pakistan, and North Korea have not ratified it. Nevertheless, the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) was established.

“When someone conducts a nuclear test, the CTBTO confirms it using its sensors, determining whether it was indeed a nuclear test, its yield, and its location. For example, when Kim Jong-un conducted his tests, the CTBTO was the organization that verified the nuclear test, its strength, and its significance,” explained the Croatian expert.

Tadić added: “What Trump actually did was an attempt to show off in front of Putin: ‘Look, we have nuclear weapons!’ As if Putin didn’t already know. ‘Now we’ll start our nuclear tests to show how strong we are!’—which is completely meaningless. Everyone in the world knows that the United States is an unparalleled superpower; they don’t need to prove their strength through military parades or nuclear tests.”

“However, what happened next? Putin immediately announced Russian nuclear tests, which is exactly what he wanted. Russian nuclear tests will serve as proof that Putin possesses powerful nuclear weapons, acting as another tool to intimidate the public in Europe and the U.S. with Russia’s nuclear arsenal. And that’s actually the worst part of the whole story. Trump, once again—intentionally or not—plays into Putin’s hands with his actions.”

Tadić concludes that we can now expect, within a few months, perhaps in about six months, a spectacular Russian nuclear test on Novaya Zemlya Island in Russia’s Arctic archipelago.

What is a real nuclear test?

According to Tadić, a true nuclear test involves testing the implosion of a plutonium core.

“To be clear: an Iranian uranium-based nuclear bomb doesn’t need to be tested—it is known to work as soon as someone has enough highly enriched uranium. A ‘gun-type’ bomb can be made by bringing together two subcritical masses, and it will work. The bomb dropped on Hiroshima (uranium) wasn’t tested—that’s precisely the concern with Iran: that over time it could have several nuclear bombs that don’t need testing because they are guaranteed to work,” Tadić explains.

“Plutonium bombs, however, are tested. Plutonium cannot simply be arranged in two critical masses that come together, because it will start reacting at even half a meter distance. Everyone realized back in 1944 that plutonium is very difficult to handle. The critical mass can only be achieved by compressing a grapefruit-sized amount of plutonium with an explosion—perfectly symmetrical from all sides—so that it reaches a higher density than natural, enabling a nuclear explosion. Achieving perfectly homogeneous spherical compression of plutonium is extremely difficult, and this is what is tested,” he continues.

Tadić emphasizes that the Russians, Chinese, and United States, as well as the French and British before them, conducted literally thousands of tests in the 1950s, 60s, 70s, and 80s. They tested warheads from half a kiloton, a few kilotons, tens of kilotons, hundreds of kilotons, up to 50 megatons—on land, above ground, in the air, in the stratosphere, at sea, and underwater.

Interestingly, he notes, most existing warheads are actually over 30 years old.

“None of us would drive a 30-year-old car, yet these nuclear warheads are expected to work reliably after 30 or more years. First, the cables and detonators degrade due to continuous radiation from the warhead, which affects synchronization needed for perfectly simultaneous compression of the plutonium core. Second, since the 1950s, no one produces purely fission bombs—there’s always a small amount of fusion fuel added,” Tadić explains.

The key question now is how to conduct a real nuclear test—a test in which the bomb actually explodes.

Above-ground or aerial tests were abandoned long ago due to environmental contamination, so most countries conducted underground tests: a horizontal tunnel is excavated, the warhead is placed at the end, and massive concrete doors are sealed at the time of the explosion. A fireball forms, hitting the surrounding rock, spreading until it cools and crystallizes.

Regarding whether Putin might conduct a surface nuclear test, Tadić comments:

“I think the whole point of Putin’s plan is precisely to create a big, beautiful nuclear mushroom cloud he can show off. If it explodes underground, it is only registered as a magnitude 5–6 earthquake. But if a large mushroom cloud appears, Putin can display it, and Dmitry Peskov can show it at press conferences.”

“That’s the purpose of the whole story, and Donald Trump enabled it by reminding him that, despite all expectations and the signed Nuclear Test Ban Treaty, the U.S. is stepping out of this framework, giving Russia full opportunity to do the same,” Tadić concludes.