South Korean President Yoon Suk Yeol’s surprise declaration of emergency martial law lasted only six hours. But it has plunged South Korea – a key Asian economy and U.S. ally – into a political crisis that could last much longer.

South Korean lawmakers began impeachment proceedings against President Yoon Suk Yeol after he briefly imposed martial law and then reversed course on that decision just hours later. Yoon claimed martial law was necessary to protect the country from "North Korea's communist forces" and to "eliminate anti-state elements.