"If Moon is elected, we will see big changes in South Korean policies towards North Korea, China and the U.S.," summed up Woo Jung-Yeop, visiting fellow at Sejong Institute, a Seoul-based think tank.
"One of the outcomes of this current situation in South Korea is going to be different foreign policy, regardless of who takes office," echoed Jonathan Berkshire Miller, international affairs fellow at the Council on Foreign Relations.
"Moon has gone on record saying he's going to put friendlier relations with the North as a higher priority. He's gone as far saying he will visit China first in order to discuss North Korea strategies," said Yang Jun-seok, professor at Catholic University of Korea. "We (South Korea) haven't tried a softer approach since Kim Jong-un came to power."
But amiable ties with Pyongyang would have broad implications for South Korea's other bilateral relationships. Washington and Beijing, in particular, may be affected, according to Miller.
"If the liberal side gets into power, they will try to delay things as much as possible to see what's going to happen," explained Yang.
Moon has repeatedly questioned THAAD implementation and has promised to review deployment if elected. The controversial system has angered China so much that the mainland has boycotted South Korean brands and even cancelled visits by Beijing tour operators.
"If Moon comes in, you're likely to have a more accommodative China political policy," said Tony Nash, chief economist at Complete Intelligence. "The South Korean economy is very entrenched to Chinese supply chains so they need to be accomodative to China if they want to succeed."