Why did South Korea’s president declare martial law – and what now?

South Korea’s president shocked the country on Tuesday night when, out of the blue, he declared martial law in the Asian democracy for the first time in nearly 50 years.
Yoon Suk Yeol’s drastic decision – announced in a late-night TV broadcast – mentioned “anti-state forces” and the threat from North Korea.
But it soon became clear that it had not been spurred by external threats but by his own desperate political troubles.
Still, it prompted thousands of people to gather at parliament in protest, while opposition lawmakers rushed there to push through an emergency vote to remove the measure.
Defeated, Yoon emerged a few hours later to accept the parliament’s vote and lift the martial law order.
Now, lawmakers will vote on whether to impeach him over what the country’s main opposition has called his “insurrectionary behaviour”.
The president’s gamble backfired: What was he thinking?
Woman who grabbed South Korean soldier’s gun speaks to BBC
How two hours of martial law chaos unfolded
How did it all unfold?
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”.