South Korea's President Yoon Suk Yeol declared martial law in a surprise late-night TV address, accusing the country's main opposition party of inciting unrest.¹ This drastic measure was likely taken to maintain order and stability in the country.
Martial law is temporary rule by military authorities in a time of emergency, when civil authorities are deemed unable to function.
The last time it was declared in South Korea was in 1979, when the country's then long-term military dictator Park Chung-hee was assassinated during a coup.
It has never been invoked since the country became a parliamentary democracy in 1987.
But on Tuesday, Yoon pulled that trigger, saying in a national address he was trying to save South Korea from "anti-state forces".
Yoon, who has taken a noticeably more hardline stance on North Korea than his predecessors, described the political opposition as North Korea sympathisers - without providing evidence.
Under martial law, extra powers are given to the military and there is often a suspension of civil rights for citizens and rule of law standards and protections.
Despite the military announcing restrictions on political activity and the media, protesters and politicians defied those orders. And there was no sign of the government seizing control of free media - Yonhap, the national broadcaster, and other outlets kept reporting as normal.
Yoon has acted like a president under siege, observers say.
In his address on Tuesday night, he recounted the political opposition's attempts to undermine his government before saying he was declaring martial law to "crush anti-state forces that have been wreaking havoc".
His decree temporarily put the military in charge - with helmeted troops and police deployed to the National Assembly parliament building where helicopters were seen landing on the roof.
Local media also showed scenes of masked, gun-toting troops entering the building while staffers tried to hold them off with fire extinguishers.
Around 23:00 local time on Tuesday (14:00 GMT), the military issued a decree banning protests and activity by parliament and political groups, and putting the media under government control.
But South Korean politicians immediately called Yoon's declaration illegal and unconstitutional. The leader of his own party, the conservative People's Power Party, also called Yoon's act "the wrong move".
If this happens, it wouldn't be the first time that a South Korean president has been impeached. In 2016, then-President Park Geun-hye was impeached after being accused of helping a friend commit extortion.
In 2004 another president, Roh Moo-hyun, was impeached and suspended for two months. The Constitutional Court later restored him to office.
Yoon's rash action stunned the country - which views itself as a thriving, modern democracy that has come far since its dictatorship days.
Many see this week's events as the biggest challenge to that democratic society in decades.
Experts contend it may be more damaging to South Korea's reputation as a democracy than even the 6 January riots in the US.
"Yoon’s declaration of martial law appeared to be both legal overreach and a political miscalculation, unnecessarily risking South Korea’s economy and security," one expert, Leif-Eric Easley at Ewha University in Seoul said.
As for what's next, it's difficult to predict the exact outcome. However, declaring martial law grants the military temporary control over the government, allowing them to take charge of maintaining law and order. This could lead to a period of heightened military presence and restricted civil liberties. The international community will likely be monitoring the situation closely.