News media reported late Monday that Kim Jong Un was in grave condition after heart surgery this month, setting off a flurry of debate among North Korea watchers. How believable are these reports? If true, what does this news mean for North Korea, the United States and the world?

What do we actually know about Kim’s health, and why do we care?

Of course, rumors on North Korea, especially regarding elite politics, often turn out to be wrong. Western media reports that Kim Jong Un had fed his uncle to dogs in 2013, for example, turned out to be a misunderstanding of a Chinese satirical website.

There were multiple false reports about the health of Kim’s father and grandfather, Kim Jong Il and Kim Il Sung. And it’s not uncommon for senior officials to leave public view and then reappear — as Kim Jong Un himself did in 2014.

In this case, a single Korean-language news source appears to be the sole source of the reports on Kim’s ill health. Officials in both South Korea and China quickly expressed skepticism. On Tuesday, U.S. intelligence officials said there was “no supporting evidence” that Kim’s health was in danger.

However, the Kim regime is unusually personalistic — and any prolonged absence tends to prompt close scrutiny from the outside world. It was unusual for North Korea’s leader to skip the commemoration of his grandfather’s birthday on April 15, a major national holiday. As Washington Post Beijing bureau chief Anna Fifield notes, Western analysts have long paid close attention to Kim’s health, as he is both overweight and a heavy smoker.

There is no question that discussions of North Korea can be prone to hype and speculation. But here’s what we do know — for the United States not to think carefully about the ramifications of political instability or transition in a nuclear-armed potential adversary would be simply irresponsible, from a strategic vantage point.

Why is succession such an issue in North Korea?

One reason this news story gained traction is that it’s unclear what would happen in North Korea if Kim died unexpectedly. Hereditary succession in a dictatorship is very rare. North Korea is perhaps the only country to pull off that feat twice in a row. But familial succession makes much more sense given the regime’s mythology and the propaganda used to justify its rule.

Within the Kim family, it’s not clear who might take over. Kim’s children are too young to rule. Much recent speculation has focused on Kim Yo Jong, Kim’s younger sister, who has played an increasing role in North Korea’s party hierarchy and public face, both domestically and abroad (after her own disappearance/reappearance last year).

Elsewhere in the world, Fidel Castro and Luis Somoza both passed power to siblings, but their siblings were adult men. Female inheritance in modern dictatorships is essentially unheard of, and North Korea watchers debate whether and how North Korea’s political culture might adapt to a female ruler.

Kim Jong Un also has a brother, Kim Jong-chul, who lives in Pyongyang and previously worked in the Korean Workers’ Party. Their father, Kim Jong Il, reportedly thought Jong-chul was unfit to rule, and this brother has reportedly kept a low profile — but by process of elimination, there aren’t many family members left. Kim Jong Un’s only other male half-sibling, Kim Jong Nam, was killed with VX nerve agent in a Malaysian airport in 2017 in what many experts believed was a North Korea-orchestrated assassination.

What does this mean for the United States?

If Kim Jong Un is incapacitated, the first question to answer for American foreign policy is whether the United States would recognize internal instability in North Korea if it occurs. This is extraordinarily hard to do, in fact. Typically the people who can block a hereditary succession are other elites, and elite politics in North Korea are especially opaque to outside observers. It’s important to recognize the limits on what the U.S. will and won’t be able to predict in dealing with a regime as secretive as North Korea.

Nevertheless, there are some important indicators. First, whoever assumes power — a Kim family member or someone else — would need to maintain control over the military and security apparatus. It’s not clear how closely the U.S. tracks this risk; former intelligence analyst and Heritage fellow Bruce Klingner suggests U.S. policy planning has considered coup risks, but former Pentagon staffer and North Korea expert Van Jackson argues that coup scenarios have not been “an analytical priority for Korea experts anywhere.”

What warning signs should analysts look for? Troop movements inside North Korea, for instance, could indicate a domestic power struggle — but if analysts outside think the changes signal an impending provocation or attack, those movements could also escalate tensions internationally.

At least for now, there have been no unusual movements reported on the peninsula — a good sign, perhaps, for both domestic stability in North Korea and international stability. But that issue could very well arise in the future. It’s worth thinking about what tools could mitigate these risks — and how party-to-party channels between North Korea and China, the inter-Korean hotline set up before the 2018 summit or the long-standing U.S-North Korea “New York channel” could be employed to reduce miscommunication and stabilize a potential crisis.

It’s also worth thinking about how well the United States is positioned to respond to a crisis. Assistant Secretary of Defense for Asia Randall Schriver departed at the end of 2019, leaving the Pentagon without a permanent point person on Asia. United States Forces-Korea (USFK) furloughed many of its Korean employees on April 1 over an ongoing disagreement on cost-sharing. Both of the U.S. aircraft carriers in the Indo-Pacific are combating the coronavirus, creating questions about U.S. military capacity and readiness in the region.

U.S.-China relations are tense amid frictions over trade, security issues and territorial conflict in places like the South China Sea — not to mention tensions over global health and international institutions like the World Health Organization. It’s been difficult to discuss North Korea scenarios with Beijing in the best of times — even on critical issues like the security of the North Korean nuclear arsenal — making effective coordination right now even less of a realistic prospect.

Kim may be fine, and North Korea may be stable — for now. But these issues aren’t going to go away. If anything, this rumor suggests an opportunity and a need for U.S. strategic thinkers to redouble their efforts to work through different scenarios of leadership change in North Korea — whether that’s prolonged incapacitation or an abrupt transition — and figure out the implications for American and international security.

Sheena Chestnut Greitens is an assistant professor at the University of Missouri and nonresident senior fellow at the Brookings Institution & CSIS’s Korea Chair. In August 2020, she will become an associate professor at UT-Austin’s LBJ School of Public Affairs. Follow her @SheenaGreitens