Election result could change U.S. options on North Korea

S. Korea votes in pivotal election
S. Korea votes in pivotal election 02:36

Last Updated May 9, 2017 10:48 AM EDT

South Koreans voted for change on Tuesday. 

The nation opted -- by a significant margin -- for a liberal presidential candidate who could completely alter the long-time strategy on dealing with belligerent neighbor Kim Jong Un to the north. 

Official poll results were to be announced later Tuesday, but as exit polling showed a landslide for Moon Jae-in, his two rivals conceded.

South Korea election 02:02

CBS News correspondent Adriana Diaz reports there were stark differences between Moon and his competitors on how to contain the growing North Korea threat, and what to do about the controversial U.S. missile defense system known as THAAD which has been deployed in South Korea.

Moon, who favors engagement with Pyongyang over confrontation, will be the first liberal politician to lead the country in nearly a decade.  

China's economic revenge 03:18

He could order the U.S. to remove THAAD, the missile defense system deployed to intercept potential short- to medium-range North Korean missiles targeting South Korea or other nearby countries. The system was rushed in by the U.S. military just weeks ago, but was met by angry protesters concerned it would only escalate tensions with the North, and with China and Russia.

On the road that leads to one THAAD installation, CBS News was stopped at a checkpoint, beyond which only military and police vehicles are permitted.

Protesters have also come as close as they can get to the anti-missile system to show their opposition. Buddhist demonstrators have been camped out at the site for 50 days, praying for THAAD's removal. At a makeshift camp down the road, demonstrators used their bodies to try and stop traffic.

"We want to make sure this military vehicle isn't carrying any supplies for THAAD," one man told us.

They want THAAD out -- despite repeated U.S. assurances it's here for their benefit.

"THAAD is here to protect South Korea, why do you oppose it?" Diaz asked.

"The only reason America deployed THAAD here is to dominate Asia," another man said. "America's presence here only raises the threat of war."

THAAD's removal would deal a blow to America's military influence in South Korea -- and a victory to China -- which fears THAAD's strong radar system might be used by the U.S. to spy on China. 

The official winner of the South Korean election will take office first thing Wednesday morning.