What has happened in South Korea and what does martial law have to do with it? [Video]

South Korea is reeling after a whiplash six hours during which the country’s embattled president declared martial law but was forced to lift it amid widespread condemnation, throwing the country’s political landscape into chaos and uncertainty.The saga began unfolding Tuesday night as most South Koreans prepared to go to sleep – prompting furious lawmakers to force their way past soldiers into parliament to strike down the decree, as protesters demanded President Yoon Suk Yeol’s removal and no return to the country’s painful authoritarian past.By dawn, the president had caved – agreeing to lift martial law. But experts say he’s dug a political grave; opposition parties are already moving to introduce impeachment measures.Questions are still swirling around the future of Yoon’s presidency, his party’s rule, and what happens next in one of the world’s most important economies and a major United States ally.Here’s what we know.What happened? What is martial law?Yoon …