This is instead a rejection of the democratic process. I don't know enough about SK's internals to say if the democratic process is already dead because of corruption (as the leader claims), or if the leader is trying to kill the process using corruption as a scape goat - but everyone should strongly lean towards the later.
The longest a French Republic has lasted is 70 years. The fifth republic is today 66 years old. The ordinary can turn into the extraordinary in an afternoon.
No, De Gaulle created the V republic with a military coup [1]. There were troops all over France, including paratroopers in Fontainebleau at 60km from Paris [0], while the "président du conseil" of the 4th republic transmitted peacefully the power to De Gaulle, to mitigate a civil war.
Wikipedia:
"The May 1958 crisis (French: Crise de mai 1958), also known as the Algiers putsch or the coup of 13 May, was a political crisis in France during the turmoil of the Algerian War of Independence (1954–1962) which led to the collapse of the Fourth Republic and its replacement by the Fifth Republic led by Charles de Gaulle who returned to power after a twelve-year absence. It started as a political uprising in Algiers on 13 May 1958 and then became a military coup d'état led by a coalition headed by Algiers deputy and reserve airborne officer Pierre Lagaillarde, French Generals Raoul Salan, Edmond Jouhaud, Jean Gracieux, and Jacques Massu, and by Admiral Philippe Auboyneau, commander of the Mediterranean fleet. The coup was supported by former Algerian Governor General Jacques Soustelle and his activist allies.
The coup had as its aim to oppose the formation of Pierre Pflimlin's new government and to impose a change of policies in favor of the right-wing partisans of French Algeria."
Legislative elections take place at the midpoint between presidential elections, and the opposition kept their majority in 2024, so there was hardly a mandate, if anything the legislative elections indicated a rebuke.
Yoon Suk Yeol is the one of the most unpopular democratic heads of state with 19% approval and 72% disapproval.
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It's worth noting that it seems like he didn't talk to anyone about this and even the head of his party in the National Assembly said they would vote to overturn it.
You don't become the leader of a developed, stable, democratic nation by pulling crazy stunts like that.
Is there any other factor to influence or any big group that would benefit from such extreme measures?
I do think he was acting by himself; he’s generally got weird political instincts. Part of how he got walloped in the legislative elections was by remarking that green onions were cheap normally because of his policies, when it turned out the supermarket he was electioneering at was running a 75% off sale on them. https://www.straitstimes.com/asia/east-asia/political-leeks-...
South Korea has had exactly one president in the modern democratic era who hasn’t been indicted after their term or impeached.