**Key Points from the article**

* SK President Yoon declared martial law, but withdrew it hours later, plunging the country into turmoil.
* The move was seen as a desperate attempt to maintain power amid growing opposition and calls for his resignation.
* Yoon's approval ratings have been low, and his wife, Kim Keon Hee, has been embroiled in corruption scandals.
* The opposition Democratic Party is moving to impeach Yoon, and even his own party leadership has demanded his withdrawal.
* The declaration of martial law has rattled South Korea's allies, including the US and Japan, and may have emboldened North Korea.
* Protests are sweeping the country, with one of the largest labour unions calling for a strike until Yoon resigns.