What is a self-coup? South Korea president’s attempt ended in failure − a notable exception in a growing global trend

South Korean soldiers try to get into the National Assembly in Seoul on Dec. 3, 2024. Chung Sung-Jun/Getty Images

Something unexpected – but hardly unprecedented – happened in South Korea on Dec. 3, 2024. With little warning, President Yoon Suk Yeol declared emergency martial law, citing the threat from “pro-North Korean anti-state forces.”

The move, which appeared more about curtailing efforts by the main opposition – the center-left Democratic Party – to frustrate Yoon’s policy agenda through their control of parliament, left many South Koreans stunned. As one Seoul resident told reporters: “It feels like a coup d’état.”

That interviewee wasn’t far off.

As scholars of authoritarian politics and authors of the colpus dataset of coup types and characteristics, we have spent countless hours documenting the history of coups d’état since World War II.

Yoon’s short-lived martial law declaration – it lasted just a few hours before being lifted – was an example of what political scientists call an “autogolpe,” or to give the phenomenon its English name, a “self-coup.”

Our data shows that self-coups are becoming more common, with more in the past decade compared with any other 10-year period since the end of World War II. What follows is a primer on why that’s happening, what self-coups involve – and why, unlike in around 80% of self-coups, Yoon’s gambit failed.

The components of a self-coup

All coup attempts share some characteristics. They involve an attempt to seize executive power and entail a concrete, observable and illegal action by military or civilian personnel.

In a regular coup, those responsible will attempt to take power from an incumbent or presumptive leader. Historically, most coups have been perpetrated, or at least supported, by military actors. A classic example is when the Chilean army under Gen. Augusto Pinochet ousted the government of Salvador Allende in 1973 and imposed military rule.

Some coups, however, are led by leaders themselves.

These self-coups are coups in reverse. Rather than the leader of the country being replaced in an unconstitutional manner, the incumbent executive takes or sponsors illegal actions against other people in the regime – for example, the courts or parliament – with the goal of extending their stay in office or expanding their own power.

This may take the form of a chief executive using troops to shut down the legislature, as Yoon tried unsuccessfully to do in South Korea. Others have had more success; Tunisian President Kais Saied orchestrated a self-coup in July 2021 by dismissing parliament and the judiciary to pave the way for expanding his presidential power. More than three years on, Saied remains in power.

Alternatively, a leader may try to coerce state officials or the legislature to overturn an election loss. We saw this happen with Donald Trump after the 2020 U.S. presidential election, and as such we include his attempt to pressure local officials – and then-Vice President Mike Pence – to overturn the election result in our list of “self-coup attempts.”

The varieties of self-coup methods

But not all executive power grabs are self-coups. For example, if a president gets the legislature to extend presidential term limits and the courts approve – as Bolivian President Evo Morales did in 2017 – this may be a blow to executive constraints and democracy, but we don’t consider it a coup since the procedure for changing the law is constitutional.

In all, we have recorded 46 self-coups since 1945 by democratically elected leaders in the forthcoming self-colpus dataset, including the latest attempt in South Korea. Our self-coup data was compiled over the past three years with the aid of some enterprising undergraduate students at Carnegie Mellon University.

Reviewing the circumstance – and outcomes – of these incidents helps us identify the most common characteristics of self-coups.

Yoon’s actions in South Korea were typical in some ways but not in others. Over half of self-coup attempts in democratic countries target the judiciary or the legislature, while around 40% explicitly seek to undermine democratic elections or prevent election winners from taking office. The rest target other regime elites or a nominal executive.

Yoon declared martial law to grab executive power from an opposition-led legislature.

Interestingly, only a quarter of self-coup attempts in democracies involve such an emergency declaration. Much more common are attacks on opposition parties and leaders and election interference.

About 1 in 5 self-coup leaders suspend or annul the constitution.

Relatively few self-coup attempts in democracies involve attempts to evade term limits, though self-coups that result in so-called “leaders for life” are becoming more common in Africa.

Why are self-coups on the rise?

Coups and self-coups are two of the most common ways democracies die, though their relative frequencies have changed over time.

Whereas coups were the leading cause of democratic breakdown during the Cold War, self-coups have become the leading cause since the fall of the Soviet Union in the early 1990s.

A third of all self-coup attempts by democratically elected leaders since 1946 have occurred in just the past decade.

Though more research is needed to account for the recent rise of self-coups, we believe part of the answer lies in the decline of anti-coup norms – in which democracies punish coup leaders by withholding recognition, foreign aid or trade deals – and the rise of personalist politics globally.

Why do self-coups fail?

Presidents and prime ministers who attempt self-coups presumably think they have a good chance of success – if they didn’t, they wouldn’t attempt a coup in the first place.

The fact that Yoon launched his self-coup bid seemingly without prior support of leaders in his own party is very unusual.

While only half of traditional coup attempts succeed, more than four out of five self-coup attempts by democratically elected leaders succeed, according to our data.

President Alberto Fujimori had the support of the military during his self-coup of 1992.
Hector Mata/AFP via Getty Images

So what went wrong for Yoon in South Korea?

Coup success depends on coordinating a lot of people, including partisan allies and military elites. Although overt military support of the kind Yoon initially received is helpful, it is not always decisive.

Most self-coup failures happen when military and party elites defect. The reasons for these defections tend to involve a mix of structural and contingent factors. When masses of people pour into the streets to oppose the coup, like we saw in Seoul, military members can get nervous and defect. And international condemnation of the coup can certainly help overturn self-coup attempts.

Public support for democracy also helps. That’s why self-coups don’t typically happen in long-established democracies like the United States that have accumulated “democratic capital” – the stock of civic and social assets that grows with a long history of democracy.

South Korea, although a military dictatorship from 1961 to 1987, has had decades of democratic rule. And the system worked in South Korea when threatened. Party leaders united to vote unanimously against Yoon.

That contrasts with successful self-coups in the country by Park Chung-hee in 1972 and Chun Doo-hwan in 1980.

What happens to failed self-coup leaders?

Rarely has a failed self-coup leader remained in office for long. The self-coup may lead them to be ousted in a coup, as occurred to Haiti’s Dumarsais Estimé in May 1950. Or they may be impeached, as occurred with Peru’s Pedro Castillo in December 2022. According to our data, only one failed self-coup leader managed to hang on to office for more than a year to the end of their term. Though not forced from office after the flawed 1994 Dominican elections, Joaquín Balaguer was forced to agree to new elections in 1996 in which he would not be a candidate.

Odds are, then, that President Yoon’s days in power are numbered. Following his attempted self-coup, six opposition parties submitted an impeachment motion against the president. That motion needs 200 of 300 members of the National Assembly to pass.

All 190 present members voted to end martial law, including 18 of 108 members from Yoon’s party. Only a few more of the conservative party’s legislators would have to vote against Yoon for impeachment proceedings to advance.

Threatened by a self-coup, South Korea’s democratic institutions seem to be holding – at least for now.

Joe Wright receives funding from the National Science Foundation and the Minerva Research Initiative

John Joseph Chin does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.