The possibility of nuclear war has frightened humanity for decades. This risk became all the more acute when Russian President Vladimir Putin brandished this threat in the context of the Russian invasion of Ukraine. However, other nuclear powers also have ongoing conflicts: India and Pakistan, both possessing nuclear weapons, clashed briefly earlier this year; Israel is attacking its neighbors, notably Iran (which is also seeking nuclear weapons); North Korea continues to threaten its southern neighbor; and the United States also very recently attacked Iran.
However, the majority of these countries are led by old men:Xi Jinping (China), Donald Trump (United States), Narendra Modi (India), Benjamin Netanyahu (Israel), Asif Ali Zardari (Pakistan), and Vladimir Putin (Russia) are all over 70 years old. These advanced ages increase the risk of chronic illness and dementia, which can affect their judgment... and plunge us into a nuclear apocalypse. This alert was sounded by researchers at the University of Otago in New Zealand, who analyzed the health data of all deceased leaders of nuclear powers, showing the extent to which a large proportion governed with health problems that could have hampered their cognitive performance. Their study was published on July 8, 2025, in the journal BMC Research Notes.
“Nuclear monarchies” that hide their leaders’ health problems
Currently, nine countries have nuclear weapons: China, North Korea, the United States, France, India, Israel, Pakistan, the United Kingdom, Russia, and the United Kingdom. And several of these countries are what researchers call "nuclear monarchies," where a single person can decide to launch a nuclear attack. This makes the health of their leaders all the more crucial, as one bad decision, influenced by illness, could be decisive. However, the health problems of men in power are often hidden from the public, even in the least autocratic countries: for example, François Mitterrand's prostate cancer in France, Dwight Eisenhower's heart attack and Ronald Reagan's onset of dementia in the United States (there are also rumors about Joe Biden's mental health), and Winston Churchill's stroke in the United Kingdom.
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Elderly leaders with frequent health problems
The authors therefore focused on leaders who had already passed away, for whom it is easier to learn such secrets. They analyzed all available data on the health of 51 leaders of these countries, based on medical reports, as well as other documents, such as biographies. Most of them were over 65 when they left office, and a third were over 75.
One in five leaders died while in office, eight of whom died from chronic illnesses. They had an average of about four known health problems. The most common causes of death were cardiovascular problems. And some had mental health problems toward the end of their terms, including Soviet dictator Joseph Stalin, the father of North Korea's current dictator, Kim Jong Il, and the founder of the People's Republic of China, Mao Zedong.
In addition to these powerful men who died from illness, 15 others had to leave power because of their illness. This group of leaders had an average of three known or suspected health problems, including cardiovascular disease, alcoholism, mood disorders (depression, bipolar disorder, etc.), partial deafness, and the onset of Alzheimer's disease, at least for one of them (Harold Wilson, United Kingdom).All 15 of these leaders could plausibly have had diminished performance due to these health problems… possibly leading to serious disruptions in their abilities, as was the case with Ariel Sharon (stroke leading to coma) or Menachem Begin (severe depression).”, explain the authors.
Measures to reduce risks
The authors also propose a series of measures to reduce the risk that health problems among leaders will lead to nuclear war. For example, they emphasize the importance of nuclear disarmament treaties. They also propose that nuclear powers commit to using these weapons only in response to a nuclear attack, and that authorization for a nuclear attack should go through several people and not rely on a single decision-maker. They also emphasize the importance of the media in investigating possible health problems among leaders to prevent them from being hidden from the public.
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