President Yoon Suk Yeol Yoon imposed martial law in the middle of the night earlier this month, plunging South Korea into its worst political crisis in decades.

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.

The president faces an accusation of insurrection and, in a first for a sitting leader, the possibility of arrest. Here’s what to know about his political future.