During his visit to South Korea this week, Donald Trump said something supposedly reassuring. The U.S. government, he noted, wants to solve the problem of North Korea’s nuclear weapons peacefully. But, if necessary, it isprepared to defend itself and its allies using the full range of our unmatched military capabilities,” which “we hope to God we never have to use.”

But as Beatrice Fihn sees it, this type of statement highlights the many problems with how we talk about nuclear weapons. Fihn leads the Geneva-based International Campaign to Abolish Nuclear Weapons, which just won the Nobel Peace Prize for mobilizing more than 120 countries to approve a United Nations treaty banning signatories from using, developing, or supporting activities related to nuclear weapons. (The treaty is now open for signatures and will become international law if at least 50 countries ratify it.) Fihn figures that if humans created nuclear weapons and attached significance to them, they are just as capable of destroying these weapons by assigning them a different meaning.

The big idea behind her campaign is simple: to relentlessly treat nuclear weapons as weapons, not as some “strategic-stability-magic power tool that relates to world peace,” she said. And not just any kind of weapon, but one that belongs in a class that, by indiscriminately targeting civilians, violates international law and has repeatedly been shunned in international treaties prohibiting biological weapons, chemical weapons, cluster munitions, and landmines.

Nuclear weapons are often described with language that obscures the ugly reality of what is under discussion, Fihn told me when we met ahead of Trump’s Asia trip. When the president references the “full range” of U.S. military capabilities, he’s presumably including nuclear weapons. But he doesn’t say that the United States, if faced with unspecified threats of unspecified gravity, is ready to use a weapon of mass destruction to indiscriminately kill civilians, irradiate survivors, and do incalculable harm to the environment and future generations, as Fihn might put it. It’s a bit like saying, “‘If someone threatens us, I’m prepared to send my entire army with machetes [to] chop everyone up in that country,’” Fihn observed. You wouldn’t say that because you would sound crazy. But that’s essentially what’s being said regarding nuclear weapons when you cut through the euphemism and abstraction.

Nuclear weapons are made all the more abstract by the secrecy surrounding them. “We don’t really know where they are or what they’re targeting or what they’re meant to be used for,” Fihn pointed out. In his remarks in South Korea, Trump announced that the U.S. had deployed aircraft carriers and a “nuclear submarine” near the Korean peninsula. What weapons they were carrying, he didn’t say.

Efforts to stop the spread and decrease stockpiles of nuclear weapons are also hampered by fundamental contradictions in how we relate to these weapons. States with nuclear weapons, for example, routinely stress the horror of such weapons even as they credit the arms with keeping their own countries safe and strong. In South Korea, for example, Trump warned that North Korea’s pursuit of nuclear weapons endangers “humanity all over the world” while simultaneously boasting about America’s “unmatched” capacity to defend itself. It’s easier, Fihn argued, to first ban and then try to get rid of nuclear weapons, “rather than trying to reduce and eliminate something that we at the same time value and say is essential for our security.”

While emerging powers such as Brazil, Indonesia, Mexico, and South Africa have signed the Treaty on the Prohibition of Nuclear Weapons, Fihn has yet to persuade any nuclear-weapons states or their treaty allies—including NATO members, Japan, and South Korea, which count on protection from their nuclear-armed partners—to support the initiative. She’s even struggling to secure the backing of countries that are more loosely allied with nuclear-weapons states but still hesitant to break with them, like her native Sweden. (“New opinion poll: 9/10 Swedes want Sweden to sign the #NuclearBan,” Fihn recently tweeted. “Who gets to decide over Swedish policy? Its people or the United States?”)

But Fihn claims she doesn’t need these holdouts, at least not right away. Her goal is to “reframe the debate” and “set a clear norm that [nuclear weapons are] unacceptable,” and then use the law to effect change. “We can’t keep murder legal just because it still happens,” she reasoned. “It’s not like we can wait until there’s no more murders ever and then make it illegal.”

She likened her efforts to anti-smoking campaigns in that she’s countering perceptions that countries with nuclear weapons are “cool.” Nuclear-weapons states sit in the UN Security Council. They’re referred to as nuclear-weapons powers. But is the tremendous destructiveness of nuclear weapons truly a measure of “power today”? she asked. As a result of smoking bans, “you can still smoke, but you do it outside,” she noted. Likewise with her treaty: “It’s like putting [nuclear-weapons states] in the cold, making them the outliers, arguing that your nuclear weapons will impact us, and that’s why we have the right to do this with or without you. ... If there’s a nuclear war, it’s not going to be contained to the countries fighting it.”

When she asks officials of nuclear-weapons states why they oppose her treaty, she’s spotted something implicit in their responses: They appear to “want others to sort of want [nuclear weapons], but not be able to have them. Because if countries don’t want [these weapons, the weapons] lose their power. So it’s in their interest to have this tension.”

As with any social-justice movement, it’s foolish to wait patiently until those with the power are prepared to give it up, Fihn said. She cited Nikki Haley, the U.S. ambassador to the United Nations, who explained that while “there is nothing I want more for my family than a world with no nuclear weapons,” she opposed the nuclear-ban treaty because “we have to be realistic.”

“You have to force the issue,” Fihn argued. Even if those in positions of power support a movement’s cause in principle, they usually say, “‘Take your time—not so confrontational. We’re not really ready. We need to find the right conditions for this. … Of course we want to, but sit down and be quiet and let us handle this.’”

Even assuming she succeeds despite the very long odds, Fihn concedes that the treaty would be only one factor among many in gradually making the world’s 15,000 nuclear warheads obsolete. Nuclear weapons are “very expensive” and rather “useless” in conflicts involving modern threats like terrorism, she said: “You’re not supposed to wipe out a whole city today. We’re going to high-tech, fully autonomous weapons—drones, that kind of stuff.” Therefore, if the nuclear-ban treaty dampens people’s estimation of nuclear weapons, “it’s going to be harder for these governments to get support for investing more money in them” and more difficult for the private sector to assist with these investments. Fihn noted that the United States didn’t sign the international Convention on Cluster Munitions, which entered into legal force in 2010. But in 2016, Textron, the last American producer of cluster munitions, stopped making the bombs, citing reduced demand for the weapon given the political sensitivities surrounding it. “It’s just a bad investment for these companies now,” Fihn said.

Nuclear-weapons states will never “sit around a table at the same time and dismantle the last” nuclear weapon, she acknowledged. “It’s just unrealistic to think that all states will feel so secure and have nothing on the horizon that worries them ever. The more likely scenario is just that [these weapons are] going to be put in storage, taken off alert, not be modernized—getting rid of them for financial reasons.”

Unlike climate change, Fihn told me, the challenge of nuclear weapons can be resolved without a drastic change to people’s way of life. She’s skeptical of the common argument that nuclear weapons are the reason why there has been no world war or major conflict between world powers since World War II. “It’s hard to say if deterrence works or not; the absence of something doesn’t prove it,” she said. “You could say I drink coffee every day and I haven’t gotten cancer, so coffee cures cancer.” The United Nations and international laws of war were also invented in the mid-20th century, she observed—maybe those institutions, not nuclear weapons, have prevented world war.

Deterrence, Fihn added, also doesn’t stop miscalculations or accidents from leading to the use of nuclear weapons. The escalating tensions between the United States and North Korea, she noted, are “a huge wake-up call … and a reminder for us that, as long as nuclear weapons exist, this could happen. And if they exist forever, it will happen.”

In the United States, Fihn observed, “Suddenly people are really uncomfortable with nuclear weapons under Donald Trump.” (Indeed, next week the Senate Foreign Relations Committee will hold hearings about the president’s “authority to use nuclear weapons”—a discussion chairman Bob Corker has described as “the first time since 1976 that this committee or our House counterparts have looked specifically” at the issue.) But Fihn says “if you’re uncomfortable with nuclear weapons under Donald Trump, you’re probably uncomfortable with nuclear weapons, because it means you recognize that [deterrence] won’t always hold up and things can go wrong. … Once you start thinking ‘this person is appropriate for this weapon but not that person,’ then maybe it’s the weapon that’s the problem.”

“Perhaps one person shouldn’t be in charge of the fate of the world,” she said.

Trump says he hopes “to God” to never have to use the full range of American military capabilities, but Fihn wants people to stop thinking of nuclear-weapons like “a natural disaster”—that “it will just happen one day and we can’t do anything about it. Like an asteroid. The world would end. The thing is, if nuclear weapons were used, the world wouldn’t end. It didn’t end in Hiroshima. It didn’t end in Nagasaki. They are cities today.”

What the bombings of Hiroshima and Nagasaki did do is bring about enormous human suffering. Fihn mentioned Setsuko Thurlow, a survivor of the Hiroshima attack who will join Fihn next month in Norway to accept the Nobel Peace Prize. Thurlow recalls, as a 13-year-old girl, “floating in the air” and crawling in “total darkness” toward “ghost-like people” whose “hair was standing up,” whose “flesh was hanging from the bones,” who were missing body parts, who in some cases “were carrying their own eyeballs in their hands,” who, “as they collapsed, their stomach burst open, intestines stretching out.”

When nuclear weapons are unthinkable, or thinkable only as a prelude to the end of the world, people feel powerless to do anything about them, Fihn said: Either nuclear war will never happen, so why worry, or it will happen and be so devastating that it’s not worth worrying. But if nuclear weapons are used, “there will be survivors,” she noted. It would not play out like a computer game. It’s not “game over.”