The impeachment of Han Duck-soo, acting president since Yoon was impeached on Dec. 14 for declaring martial law, has thrown South Korea's once-vibrant democratic success story into uncharted territory.

South Korea’s opposition-controlled National Assembly voted Friday to impeach acting President Han Duck-soo despite vehement protests by governing party lawmakers, further deepening the country’s political crisis set off by President Yoon Suk Yeol’s stunning imposition of martial law and ensuing impeachment.

Han’s impeachment occurs amid weeks of political chaos following Yoon’s brief declaration of martial law on December 3, which lasted only six hours but led to widespread protests. This move intensified the political vacuum that has gripped South Korea.