Amid an apparent historic diplomatic rapprochement between the two Koreas, North Korean leader Kim Jong Un has hinted that his country might end its nuclear testing and eventually give up its atomic weapons.

There are reasons to be skeptical. Yes, Libya suspended its own nuclear-weapons program in 2003. But that program amounted to little more than exploratory research. Libya had no functional weapons.

Since the United States tested the first nuclear bomb in July 1945, just one country—South Africa in the late 1980s and early ’90s—has voluntarily ended a well-established nuclear-weapons program and dismantled a functional atomic arsenal.

But North Korea is not like South Africa. It could be difficult to duplicate, in Pyongyang, the internal and external forces that propelled Cape Town's own denuclearization. For that reason, there’s reason to believe Kim’s conciliatory gestures might merely be a negotiating tactic.

“If North Korea agreed to disarm, right after having by their own account attained an intercontinental thermonuclear capability, it would be completely unprecedented,” Alex Wellerstein, a nuclear historian at the Stevens Institute of Technology in New Jersey, told The Daily Beast. “This is one of many reasons to be skeptical that there is much chance of it happening.”

There are some parallels between South Africa and North Korea. Both countries were essentially alone and surrounded by enemies when they decided to acquire atomic weapons—South Africa in the mid-1970s and North Korea in the 1980s.

The ’70s was a dangerous decade for South Africa. Across the continent, the Soviet Union was backing liberation movements that Cape Town viewed as threats. Cuban advisors were in nearby Angola. Cut off from the wider Western world because of apartheid, South Africa considered nukes to be the ultimate security guarantee.

By the late 1980s the country possessed six small atomic bombs and British-made Buccaneer bombers to drop them. But experts say that even these modest weapons were overkill for South Africa’s strategic situation. “It wasn’t clear what they thought they would use them for,” Wellerstein said.

That’s not just one professor’s opinion. “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,” F.W. de Klerk, South Africa's last apartheid president, told The Atlantic in 2017.

By contrast, Kim and his regime “have developed weapons that appear to be quite sophisticated and have done so with a clear strategic goal in mind,” Wellerstein explained.

That goal, of course, is to deter the United States and South Korea and their allies from attacking North Korea and threatening a regime that has ruled the country since its split from the South in 1948.

South Africa never faced what Wellerstein described as an “existential” external threat that compelled it to cling to its nukes. Even during the tumultuous 1970s, the country’s most profound conflict was internal. De Klerk was elected in 1989 as international pressure and domestic protest finally began unraveling four decades of official state racism.

The country craved ties to the wider world. The “meaningless” six-bomb nuclear arsenal stood in the way. “From the beginning, in my personal opinion, I regarded it as a rope around our neck,” de Klerk said.

In 1993, South Africa announced it had dismantled all six weapons and permanently ended the research and production efforts behind them. For the first time ever, a country had given up a functional atomic arsenal.

It was a heady era for proponents of a nuclear-free world. Around the same time, the former Soviet republics of Ukraine, Kazakhstan, and Belarus returned to Russia the atomic weapons that the newly independent countries had inherited during the breakup of the USSR. But the former Soviet states never actually had the authority and technology to launch the USSR’s old nukes.

South Africa’s was a special case—and the closest parallel to North Korea’s own situation two decades later. “Like South Africa, [North Korea] developed a fully fledged nuclear program in defiance of internal opprobrium and sanctions,” Mariana Budjeryn, a Harvard nuclear expert, told The Daily Beast. But the similarities end there, and that’s important for understanding experts’ skepticism toward Kim’s new peacenik persona.

Unlike South Africa in the late 1980s and early 1990s, North Korea apparently isn’t undergoing some kind of radical domestic transformation into a freer and more open country, one that rejects weapons of mass destruction and foreign relations founded on fear and mutual threats.

That being the case, experts say Kim’s offer to end nuclear testing and eventually, maybe, give up his nukes is a rhetorical opening move in a long diplomatic game that the autocrat hopes will yield economic and security benefits for his regime without necessarily resulting in full nuclear disarmament. “Suspending testing is a good-faith gesture and bargaining ploy that yields what Kim wants out of his testing program, politically,” Bruce Blair, a Princeton nuclear expert, told The Daily Beast.

Halting the test program doesn’t necessarily cost North Korea much, Budjeryn noted. And it’s definitely not the same thing as scrapping all existing nukes. “North Korea had six nuclear tests, the same as Pakistan, and probably sufficient to gather the technical information they need.”

Actually dismantling the small number of atomic warheads it has produced—not to mention the associated long-range ballistic missiles—would deprive North Korea of the very thing that has allowed the isolated, impoverished country to negotiate as an equal with the wealthier South and the even richer and more powerful United States.

“What in the world could induce them to renounce it?” Budjeryn asked of Pyongyang’s atomic arsenal. “I would expect that a genuine decision to dismantle these programs would come on the back of a regime change or at least a radical redefinition of what kind of state North Korea is and how it relates to the outside world and the international community.”

“Is Kim Jong Un capable of such a radical redefinition?” Budjeryn continued. “Has he drunk the Kool-Aid and realized that he can’t keep his country isolated and poor and now that he’s proven he can build the bomb he wants to open it up on his own terms?... To ascertain it, we’ll have to see what he is prepared to do internally, not just internationally.”

In South Africa, de Klerk felt domestic pressure to begin ending South Africa’s isolation by first giving up atomic weapons. “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], 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,” he told The Atlantic.

“Inner conviction weighs heavier on the scale than international pressure,” de Klerk said of his own decision to dismantle South Africa’s nukes. Does Kim feel the same conviction in a country with no free elections, where his word is final? Where the government controls information and communications? Where authorities imprison or even kill anyone who questions Kim’s whims?

The key to divining Pyongyang’s willingness to truly end its nuclear program is looking for evidence of domestic political reform, Budjeryn said. “If domestically North Korea is more of the same, then Kim’s rhetoric is just more of the same old ploy we’ve seen before: ratcheting up the program to get concessions from the West, only to restart it again a few years down the road with new rigor.”