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 to impeach acting President Han Duck-soo, further deepening the country's political crisis.

The impeachment of South Korea’s acting President Han Duck-soo has plunged the country into further political turmoil, coming less than two weeks after lawmakers impeached President Yoon Suk Yeol.