North Korea’s increasingly sophisticated missile and nuclear tests indicate that the nation’s nuclear-arms program is rapidly advancing, nearing the point at which Kim Jong Un can credibly claim to possess the means of nuking the United States. But they also demonstrate something else: No matter how many sanctions you impose, no matter how much you threaten fearsome displays of military power, it is very hard to convince a country to abandon the pursuit of nuclear weapons—especially when that country has progressed far enough to acquire those weapons, like North Korea has.

Only four countries in history have surrendered their nuclear weapons. And three of those countries—Belarus, Kazakhstan, and Ukraine—did so with nuclear arms that they inherited from the defunct Soviet Union, and didn’t have the wherewithal to control and maintain. (The decision to dispose of this weaponry, in exchange for support from the United States and security assurances from Russia, is still remarkable; had Ukraine and Kazakhstan kept the arsenals on their territory, they would have become the world’s third- and fourth-largest nuclear powers, respectively.)

Only South Africa has dismantled nuclear weapons that it constructed and controlled. In this sense, it is the closest analogue to what U.S. officials have in mind when they demand the “denuclearization of the Korean peninsula.” I recently spoke with the man who made that singular move—the former South African President F.W. de Klerk—about why he decided to do what he did and what lessons his experience offers for how to resolve the North Korean nuclear crisis. (You can find a broader discussion of the historical precedents here.) Below is an edited and condensed transcript of our conversation.

Uri Friedman: Why did the South African government, in the mid-1970s, decide to embark on a nuclear-weapons program?

F.W. de Klerk: The main motivation was the expansionist policies of the U.S.S.R. in southern Africa. They were supporting all the [African] liberation movements—they were supplying weapons and training—and it was part of their vision to gain direct or indirect control over most of the countries in southern Africa. They financed the deployment of many thousands of Cuban troops, especially to Angola, and this was interpreted as a threat first by Prime Minister John Vorster, and following upon him P.W. Botha. [The nuclear arsenal] was never intended, I think, to be used. It was a deterrent. Because of apartheid South Africa was becoming more and more isolated in the eyes of the rest of the world. There wouldn’t be, in the case of Russian aggression or invasion, assistance from the international community. It was felt that, if we have nuclear weapons, and if we then would disclose in a crisis that we have [them], it would change the political scenario and the U.S.A. and other [Western] countries might step in and assist South Africa.

Friedman: So you would inform a country like the United States that you had these weapons and therefore they might intervene to stop you from using them against the Soviet Union. Was that the idea?

De Klerk: Exactly. I first became aware of the existence of this program—the full cabinet in South Africa never knew about it—when I became minister of mineral and energy affairs [in the early 1980s]. The bombs were in the making. I never felt comfortable with [the program], but I couldn’t stop it. By the end, when I became president, we had six completed nuclear weapons, and the seventh was halfway done. They were Hiroshima-type weapons.  

Friedman: Why did you have misgivings about the program?

De Klerk: I felt that it’s meaningless to use such a bomb in what was essentially a bush war—that it was unspeakable to think that we could destroy a city in one of our neighboring countries in any way whatsoever. From the beginning, in my personal opinion, I regarded it as a rope around our neck.

Friedman: In what sense?

De Klerk: In the sense you have something which you never intend to use, really, which is unspeakable to use, which would be morally indefensible to use.

Friedman: In 1989, when you became president and decided to dismantle the program, what, beyond your personal feelings about nuclear weapons, made you convinced that it was a good decision to dismantle South Africa’s weapons?

De Klerk: With the coming down of the Berlin Wall, and the breakup of the U.S.S.R., the threat of Soviet communist expansionism fell away. Simultaneously, I took initiatives to start a constitutional dialogue and to bring an end to apartheid. A peace accord was signed [in Angola], the Cuban troops were withdrawn, [the southern African state of] Namibia became independent. All those factors brought us to the point where, even if you were a supporter of having nuclear weapons, the rationale for that fell away and the nature of [the] threats changed fundamentally.

Friedman: You’ve mentioned a few different motivations: One, your own feelings; two, the security environment changing; and three, the desire to end South Africa’s international isolation and make the transition from apartheid. Is there a way to rank those?

De Klerk: It was a combination of everything, but I can add to that that I wanted to end the isolation even before we finalized agreements through the constitutional negotiations. And one of the important things to achieve re-acceptance into the international community would have been to take an initiative, without any pressure from outside, to bring this program to an end, to sign the [nuclear nonproliferation treaty, or NPT], to dismantle our nuclear weapons and to prove to the world that we weren’t playing games, but that we were very serious about fundamental reform in South Africa.

Friedman: Did you face pressure within your own government about making that decision? After all, you had sunk hundreds of millions of dollars into the program—it was a powerful form of deterrence against an attack on South Africa. Were there fellow officials who said, “No. Don’t do it. This is a terrible idea?”

De Klerk: Well, there was no pressure on me to initiate the dismantling [of the atomic bombs] and signing the NPT. There was some resistance from the defense force to say, “You shouldn’t give away something you have already.” But I overrode that opposition.

Friedman: Were you yourself conflicted?

De Klerk: No, I wasn’t internally conflicted, I was convinced that I was doing the right thing, in the best interest of South Africa. I also combined it with an effort to say that Africa should be a nuclear-free continent. I am anti-nuclear weapons.

Friedman: Do you still feel it was the right decision today?

De Klerk: Yes. I never doubted it.

Friedman: When The New York Times wrote about the decision in 1993, they mentioned suspicion that one of the reasons the South African government decided to relinquish its nuclear weapons was that it distrusted the transitional government [eventually led by Nelson Mandela]. [“Many suspect the government was also motivated by a desire to prevent its atomic weapons from someday falling into the hands of a black government,” the Times noted.] Is there truth to that?

De Klerk: No, that was not part of my motivation—that I wanted to keep the weapons out of their hands.

Friedman: In an op-ed in 2013 in the Los Angeles Times, you wrote, “South Africa has illustrated that long-term security can be far better assured by the abrogation of nuclear weapons than by their retention.” It seems that Kim Jong Un of North Korea has, at least according to his propaganda, learned the opposite lesson: that if you’re [Libya’s Muammar] Qaddafi or Saddam [Hussein in Iraq] and you give up your [pursuit of] nuclear weapons, you reduce your security [and bring about your demise at the hands of the U.S. and its allies]. Or if you’re Ukraine and you sign up to the Budapest Memorandum, and then Russia two decades later invades you, that you’ve actually given up security by relinquishing nuclear weapons.

De Klerk: I still agree with [what I wrote]. Ultimately, the world will be safe only when all the nuclear states follow South Africa’s example and dismantle their nuclear weapons.

Friedman: What lessons does your experience offer about the circumstances under which Kim Jong Un might roll back or eliminate his nuclear-weapons program?

De Klerk: It is an open question whether the dictator of North Korea can be brought to reason in this regard. So far, sticks have been used [against North Korea]. Maybe the time has arrived to also say, ‘Can we devise a carrot which can bring people around the table that are not talking to each other at the moment? What should that carrot look like?’ Whether there is enough reasonableness and sanity on the side of North Korea to take a meaningful look at an offer of a carrot is another question. Nobody can change that if it’s unchangeable.

Friedman: It seems Kim Jong Un doesn’t share your personal convictions about nuclear weapons.

De Klerk: I agree with that, but if he sits down with his immediate neighbor South Korea and if they can work out a peace treaty [to formally conclude the Korean War, which ended in an armistice], then the threat to [North Korea] will also change. I’m not pleading for the removal of the stick. What I am saying is that the lesson we’ve learned in South Africa, in a wider context apart from nuclear weapons, is that only through negotiation, only if enemies or opponents talk to each other, can peace be achieved, can a new dispensation be agreed upon. If you don’t talk, you get thrown deeper and deeper into more conflict.

Friedman: You weren’t exactly facing carrots and sticks on South Africa’s nuclear-weapons program from the international community?

De Klerk: Not on the nuclear-weapons program. I didn’t ask for a carrot and there was no real stick involved.

Friedman: But there were in terms of apartheid. There were sanctions, there were efforts at negotiation.

De Klerk: On the issue of apartheid there were very strong pressures upon us. But in the end, we took the initiatives we took, which I announced on February 2, 1990, not because of international pressure, but because we came to a situation where we accepted the moral unacceptability of apartheid and continued racial discrimination, where we admitted that it was wrong. I made a profound apology about the harm and the pain and the suffering that apartheid had caused. Inner conviction weighs heavier on the scale than international pressure.

Friedman: To those who say, ‘Once countries get nuclear weapons, they’re never going to give them up. We just have to live with a nuclear weapons-armed North Korea,’ what would you say?

De Klerk: I would say the solution lies in those [nuclear-weapons powers] who, even if [they have nuclear weapons] legitimately in terms of the NPT, coming forth and showing their willingness, in a reasoned way, to diminish their stocks and to commit to an end goal of getting rid of it all—to lead by example.