Threat of Nuclear War Is Rising, But Scientists Say the Public Can Change That

Scientists and others are calling on civil society to heed growing nuclear dangers and revive the anti-nuclear movement.

By Jon Letman , Truthout

PublishedAugust 4, 2025

An estimated 1 million people rally for nuclear disarmament in Central Park, New York City, on June 12, 1982.Owen Franken / Corbis via Getty Images

Eighty years after two U.S. atomic bombs killed between 110,000 to 210,000 people in Hiroshima and Nagasaki, Japan, public awareness of nuclear risks has fallen to new lows, said Laura Grego, senior scientist and research director with the Union of Concerned Scientists.

“I think people don’t know how terrible nuclear war would be,” Grego told Truthout on July 16 — 80 years to the day since the first-ever atomic detonation in New Mexico. The Trinity test was conducted just three weeks before the U.S. dropped two atomic bombs on Japan.

Brian Schmidt, an American-Australian astrophysicist who received the Nobel Prize for physics in 2011, pointed out that many of today’s nuclear weapons are far more destructive than the bombs used in the horrific Hiroshima and Nagasaki bombings. In contemporary arsenals, a single bomb can contain as much destructive power as was unleashed in all of World War II.

Currently, the world’s nine nuclear-armed nations are estimated to possess the destructive equivalent of 146,500 Hiroshima-sized bombs, many of which are ready to launch on short notice.

Schmidt told Truthout that even a “small” nuclear weapon could precipitate the use of a gigaton’s worth of nuclear arsenal being used, causing the collapse of civilization.

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“I think the public needs to be focused on asking our respective governments to lower the risk of nuclear war,” he said.

Nuclear Spending Is Rising as Arms Treaties Are Abandoned

Today, nuclear weapons spending is rising, nuclear-armed nations are modernizing and upgrading their weapons, and China is rapidly expanding its arsenal. Currently, the U.S. has seven modernization programs underway, is building two new nuclear weapons facilities, and replacing its entire intercontinental ballistic missile force with a new system that is 81 percent over budget. The U.S., which spends more on nuclear weapons than the other eight nations combined, is forecast to spend an average of $95 billion per year over the next decade, according to the Congressional Budget Office.

In contemporary arsenals, a single bomb can contain as much destructive power as was unleashed in all of World War II.

In recent years, nuclear threats have become increasingly common while diplomacy and dialogue are overshadowed by mistrust, conflict, and war. As reliance on nuclear weapons grows, there are fears of a new arms race and possible return to nuclear explosive testing. This comes as critical arms treaties have been abandoned or face an uncertain future.

In 2001, George W. Bush announced the U.S. would withdraw from the Anti-Ballistic Missile Treaty, and under Donald Trump, the U.S. has rejected or withdrawn from the Intermediate-Range Nuclear Forces Treaty, the Open Skies Treaty, the (conventional) Arms Trade Treaty, and the 2015 Iran nuclear deal. The last remaining nuclear arms control agreement between the U.S. and Russia, the New START Treaty, will end in February 2026 unless it is renegotiated or replaced soon.

After World War II, the U.S., followed by the Soviet Union, invested heavily in developing nuclear weapons, with the U.K., France, China, and later Israel, India, Pakistan, and North Korea building their own bombs. In the mid-1980s, global nuclear arsenals peaked at just over 70,000 warheads. Arms control treaties and diplomacy succeeded in reducing those numbers to roughly 12,200 today, nearly 90 percent of which are possessed by Russia and the United States.

While some argue that nuclear deterrence provides safety and security, many in the arms control and scientific communities believe that the threat of nuclear war has never been higher. In the first six months of 2025, five nuclear-armed countries (Russia, India, Pakistan, Israel, and the United States) have engaged in military hostilities or outright war, increasing the risk of nuclear war by accident, miscommunication, or design.
Warnings and Solutions

Last month, on the Trinity test anniversary, an assembly of more than a dozen Nobel Prize laureates and some 60 nuclear experts gathered for three days of discussions at the University of Chicago to come up with practical, actionable steps that can be taken now to reduce the risk of nuclear war.


The world’s nine nuclear-armed nations are estimated to possess the destructive equivalent of 146,500 Hiroshima-sized bombs.

In a press conference, the group presented a two-page declaration for the prevention of nuclear war signed by 120 Nobel laureates representing six disciplines and at least 45 nuclear experts. Among their recommendations was a call for every nation to publicly recommit to all nonproliferation and disarmament objectives and obligations, to reiterate commitment to the nuclear explosive test moratorium, and for Russia and the U.S. to enter into immediate arms control negotiations. They also called on scientists, academics, civil society, and communities of faith to “create the necessary pressure on global leaders to implement nuclear risk reduction measures.”

Speaking at the university, Cardinal Silvano Maria Tomasi, an adviser to Pope Leo XIV said, “The Trinity explosion taught us what we are capable of destroying. The task before us now is to rediscover what we are capable of preserving and building.”

The choice of venues was intentional as the University of Chicago was where key steps in the Manhattan Project were achieved, where the Bulletin of the Atomic Scientists was founded, and where the symbolic Doomsday Clock was created to communicate threats to humanity and the world. Today, the clock is set at 89 seconds to midnight — the closest it has ever been to global catastrophe.
Headed in the Wrong Direction

Alexandra Bell, president and CEO of the Bulletin of the Atomic Scientists, points out that the Chicago assembly wasn’t the first time Nobel laureates have called for leaders to rein in nuclear dangers. But now, after decades of “slow, tedious, difficult progress” to create restraints to prevent a nuclear catastrophe, the world has reached a reckoning point: “Those [structures] are crumbling and we seem to be heading in the wrong direction,” she says.

Although we have the diplomatic and political tools as well as the historical background to reduce risks, Bell says today’s leaders lack the necessary ambition and will. This raises the question: Will our luck hold out?

“The odds are not in our favor,” she says.


The last remaining nuclear arms control agreement between the U.S. and Russia, the New START Treaty, will end in February 2026 unless it is renegotiated or replaced soon.

Yet even in the face of nuclear peril, she understands why people seem more concerned about the price of eggs. In addition to so many other concerns, Bell says, people still need to care about nuclear war because the threat has never gone away. She insists that ordinary people do have a role to play and can have an impact by pressuring elected officials or simply starting a conversation with each other.

“This affects all of us,” says Bell. “And if we get the nuclear problem wrong, nothing else matters.”
More Weapons, More Risks

In a time of growing geopolitical tension and instability, when international norms are under stress, competition between nuclear weapon states means greater nuclear risks, says Mallory Stewart, executive vice president at the Council on Strategic Risks.

Stewart told Truthout that it’s important to dispel the perception that nuclear risk reduction is an esoteric, political issue only for experts, and bring an end to public complacency: “It would be nice if the public felt some agency to say, ‘It’s not as simple as arms racing. It’s not as simple as might makes right. There is a deeper threat to humanity.’”


“The Trinity explosion taught us what we are capable of destroying. The task before us now is to rediscover what we are capable of preserving and building.”

“Growing reliance on nuclear weapons and modernization or more weapons will just lead to more weapons and modernization on the other side,” Stewart says.
Understanding and Engagement

James McKeon, a program officer for nuclear security at the Carnegie Corporation of New York, encourages people to educate themselves about arms control, nonproliferation, or the basics of nuclear technology. “It’s no more complicated than any other scientific topic,” he says, pointing to resources that clearly explain the science, history, and policies of nuclear issues.

McKeon says we need new ways for artists, writers, and creative individuals to think about nuclear policy. An engaged citizenry, he says, is more likely to reach out to elected officials and understand that the risk of nuclear weapons hasn’t gone away and is compounded by new technologies.

Robert Latiff is a retired major general in the Air Force who teaches weapons ethics and how new technology impacts the laws of armed conflict at Notre Dame University. “There is absolutely no ethical argument for nuclear weapons,” he says. He prefers not to call them “weapons” because they can’t be used to fight a war. “They’re more devices of terror than they are weapons,” he says. “Fight a war with nuclear weapons and what do you have left?”

Latiff points to George H. W. Bush’s 1991 Presidential Nuclear Initiatives which took unilateral action to remove U.S. tactical nuclear weapons from Europe and South Korea. He says that with moral courage, a U.S. president could again have a huge impact on nuclear policy.
Climate of Fear

Wole Soyinka, a Nigerian playwright and recipient of the 1986 Nobel Prize for literature, also came to Chicago to grapple with how to reduce nuclear risks. “We do have an enhanced climate of fear right now,” he told Truthout.


This affects all of us. And if we get the nuclear problem wrong, nothing else matters.

“It isn’t only global warming that we are witnessing. There’s a certain heating up of, shall we say, human and social relationships and national interaction,” says Soyinka. He describes a “disturbing escalation of violence” and a “kind of demonic sweep of leadership” in which politicians blithely declare, “if necessary, I will use an atom bomb,” and display what he calls “boastful, arrogant, hubristic body language” and terms like “little rocket man” and “obliterating unilaterally.”

Since 2009, the African continent has been designated a nuclear-weapon-free zone under the Treaty of Pelindaba. Africa is often left out of the nuclear conversation, but it was in the colonized Algerian Sahara that France conducted 17 nuclear weapons tests in the 1960s over the protests of African nations.

“If there is an atomic war in Ukraine, even Africa would be affected. We probably see that reflected more and more in the literary arts as well as the graphic arts,” Soyinka says. “Many people still believe that political leaders are people of common sense and that has never happened. My imagination has gone over and beyond that, and I wake up sometimes wondering what will be the next global conflagration.”
Uprooting the Nuclear Order

Laura Grego from the Union of Concerned Scientists warns that when the U.S. military makes war plans, it doesn’t include the full spectrum of what would happen in a nuclear war, saying, “I think they don’t want to know the answer because it’s terrible.”

Grego told Truthout that military expectations for nuclear war can be found in National Academies reports, which she believes likely undercount the long-term effects of radioactive fallout, possibly by as much as a factor of 10. Nuclear winter, major disruptions to agriculture, and mass starvation are long-term consequences of nuclear war that are usually not counted by military planners, Grego says. “We’re running risks that we don’t fully understand.”


We’re a democracy and our responsibility is to make sure our policies align with our democratic values, with our hopes for the world, hopes for a long-term future for our children that is healthy, secure, and sustainable.”

The Nobel declaration calls on all nations to increase investment and cooperative research on the environmental, social, military, and economic impacts of nuclear conflict, and to support a UN Independent Scientific Panel on the Effects of Nuclear War.

Grego is also concerned about the expanding role of nuclear weapons. “Russia has recently changed their nuclear policy to say that they’re meant to deter nuclear powers that are helping a non-nuclear adversary,” she says, adding that the role of nuclear weapons should be reduced and that by investing heavily in modernization, we are disincentivizing the reduction of nuclear weapons. Investing in nuclear weapons, she says, indicates we expect them to be around for another 80 years.

“We need to find a way to wean ourselves off the reliance of [nuclear weapons],” Grego says, noting that the leader of a major nuclear-armed country could transform the world by eliminating nuclear weapons with a verified plan and encouraging others to join them. Doing so, however, would surely mean facing powerful, determined opponents who are invested in maintaining the status quo. Grego hopes global leaders will demonstrate a commitment to political courage over simply seeking unilateral security advantages.

In her interactions with members of Congress, Grego says they report almost never hearing their constituents bring up nuclear weapons. It’s not enough for the public to be scared or angry at how we’ve organized our security, she says. “We do need to further engage. We’re a democracy and our responsibility is to make sure our policies align with our democratic values, with our hopes for the world, hopes for a long-term future for our children that is healthy, secure, and sustainable.”


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Jon Letman  is a freelance journalist on Kauai. He writes about nuclear weapons, militarism, human rights and the environment in the Asia-Pacific region and beyond. Follow him on Bluesky.