The Doomsday Clock has stood at 1 minute and 25 seconds to midnight since January 2026, the highest level ever recorded. Driving the clock forward are five crises involving nuclear powers: Russia-Ukraine, Israel-U.S. vs. Iran, India-Pakistan, North Korea’s entry into the nuclear club, and tensions between China and Taiwan.

After decades of being an absolute taboo, in fact, the use of nuclear weapons is no longer unthinkable. Technically, a bomb can be deployed with limited radioactive fallout if detonated at high altitude, making it a viable military option beyond deterrence.

The Cold War demonstrated that the superbomb made total war between superpowers impossible thanks to Mutual Assured Destruction. Today, however, smaller or struggling nations (Israel, Pakistan, North Korea, Russia, Iran, and the US itself) might consider its tactical or demonstrative use when they feel their survival is threatened.

While in Russia, the influential advisor Karaganov suggests the demonstrative use of an atomic bomb in the ongoing conflict with Iran, the U.S. and Israel might be tempted to use nuclear “bunker-buster” weapons against underground facilities. Iran, for its part, following the assassination of Khamenei, could accelerate its nuclear program by setting aside the moral qualms that have held it back until now.

The nuclear taboo is crumbling: for the first time since the 1950s, there is concrete talk again of the possible use of nuclear weapons in a real conflict.

EXECUTIVE SUMMARY

• After Hiroshima and Nagasaki, the use of nuclear weapons became a political and cultural taboo, one that is, however, gradually weakening in the current crises.
• Nuclear bombs are not indiscriminate apocalyptic weapons; they are devices that certain actors might deem rational to use when the cost-benefit ratio is favorable, especially with high-altitude detonations that minimize radioactive fallout.
• The risk of contamination is relative and manageable; airbursts produce negligible fallout (as demonstrated in Hiroshima and Nagasaki), while only ground detonations generate significant fallout.
• Today, five dangerous situations involve nuclear powers: North Korea’s entry into the nuclear club, the Russia-Ukraine conflict, India-Pakistan clashes, the China-Taiwan crisis, and a U.S.-Israel war against Iran.
• In contexts of existential threat or conventional stalemate, rational powers could break the nuclear taboo with tactical or demonstrative weapons; deterrence remains strong, but no longer absolute.