Yoon Suk Yeol, South Korea’s since-impeached president, had been planning for months to impose martial law and target political opponents, according to accounts.

The unexpected martial law decree and swift political fallout shocked the nation and economic markets, unsettling key allies the United States and Europe which had seen Yoon as a staunch partner in global efforts to counter China, Russia, and North Korea.

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.