South Korea’s diplomatic and security relations with Japan experienced a dramatic turnaround under Yoon. Tokyo fears that progress won’t last under a new president.

For the United States, the turmoil in South Korea is potentially disruptive to its geopolitical agenda in East Asia.

South Korea's main opposition party vowed on Tuesday to impeach acting president Han Duck-soo but reversed an earlier plan and decided to wait until later in the week, party officials said, as the risk of further political uncertainty heightened.

America must assess whether the next South Korean president would continue the policies of Yoon Suk Yeol, a supporter of U.S. foreign initiatives.

The lawyers for a former South Korean defence minister under investigation on insurrection charges said on Thursday a short-lived martial law decree imposed earlier this month was to raise alarm on opposition parties' abuse of the democratic process.

South Korea’s President Yoon Suk Yeol again declined to appear for questioning by investigators over his martial law declaration as the embattled leader seeks to first defend himself at an impeachment trial.

South Korea's suspended President Yoon Suk Yeol did not respond on Wednesday to a second summons by anti-corruption authorities who, along with prosecutors, are investigating his short-lived martial law decree issued early this month.

South Korea’s main liberal opposition party said Tuesday it will seek to impeach acting leader Han Duck-soo, as Seoul grapples with the turmoil set off when impeached President Yoon Suk Yeol made a short-lived declaration of martial law.