It has been a very good week for South Korean President Lee Jae Myung.

He had two very successful visits to Tokyo and Washington, with positive and productive meetings with Prime Minister Shigeru Ishiba and U.S. President Donald Trump, respectively. Neither outcome was assured.

He and his team deserve credit for both successes, but the applause will fade quickly. Now comes the hard work: ensuring that the fruits of both meetings endure and South Korea’s relations with Japan and the United States stay on the right path. It will take more than momentum to achieve that result.