South Korea elected the left-leaning Moon Jae In as its next president today, bringing almost a decade of conservative rule of the country to an end.
Liberal Moon, 64, ran for president against conservative Park Geun Hye in 2012. He lost narrowly - only to win five years later after Park was ousted for corruption.
But though South Korea's domestic politics likely played the largest role in Moon's victory, his win will have international consequences - including for President Donald Trump's policy towards North Korea.
Moon is an outspoken advocate of dialogue with North Korea, and open to returning the Blue House to what used to be known as the "Sunshine Policies," of greater engagement with the North.
As chief of staff to President Roh Moo Hyun during Roh's term from 2003 to 2008, Moon was part of an administration that pursued exactly that, increasing political and economic contact with North Korea in an effort to keep the peace.
Trump, for his part, has vowed a much tougher line on North Korea and its missile and nuclear programme, declaring that years of US "strategic patience" are at an end. He's also tried to strongarm and sweet talk China into playing a more helpful role in dealing with Pyongyang - stances that jelled well with the conservatives who've ruled South Korea for a decade, but which clash with Moon's likely approach.
Of course, a lot has changed in those 10 years that could make "Sunshine" policies less practical. North Korea's nuclear capabilities have increased in the meantime, and UN sanctions have been put in place, which may make it difficult for Moon undertake some cooperative ventures that he has proposed, such as reopening the Kaesong industrial complex, the joint North-South factory project that closed last year.
Nevertheless, Moon, the son of a North Korean refugee, has been critical of Park's hard line towards North Korea, and will likely try to ensure a stronger dialogue mechanism is in place with his country's northern neighbour.
What does that mean for the future of the US Terminal High Altitude Area Defence (THAAD) anti-missile system? It's not entirely clear. Moon hasn't called outright for the cancellation of THAAD, Douglas Paal of the Carnegie Endowment pointed out, but he has said it needs to be reviewed.
But facts are building on the ground. The THAAD was deployed to a South Korean golf course in March and is now initially operational. Politics aside, that might make it hard to pull the missile defence system now, said Lisa Collins of the Centre for Strategic and International Studies.
If Trump reiterates his demands that South Korea pay for THAAD, it could create a sore spot in relations.
But a South Korea under Moon will finally bring some stability to politics in Seoul, which have been rocked for months by corruption and scandal. Washington had got used to issuing diktats to South Korea - and will have to relearn old habits, Paal said.
The United States needs to "restart the practice of interacting with a government," he said. "We won't unilaterally set the agenda."