Particularly after the election of the progressive Moon Jae-in as president of South Korea, it is opportune to consider whether American policy toward the North is due for a radical rethinking.

Affirmative findings would give the president statutory authority to raise import barriers to protect domestic sources. But invoking national security to justify protectionism is an extreme measure—the “nuclear option” of international trade law—that would generate some undesirable consequences for U.S.-China relations, as well as for the rules-based trading system itself.

Both the Chinese Communist Party and People’s Liberation Army have a special interest in the PRC’s relationship with the North. But presidents Xi Jinping and Donald Trump seem to understand each other on the Korean Peninsula issue, and there may be no better opportunity for the U.S. and Chinese governments to come to an understanding.

The US Secretary of State’s visit to Beijing, and his meetings with the Chinese foreign minister, ended with a pledges by both to resolutely advocate denuclearization of the Peninsula, strictly implement UN resolutions and strive for a peaceful resolution. That realistic assessment by both sides is a good omen for more collaboration between Washington and Beijing.

China and the U.S. will hold their first summit meeting this week. Though the concrete schedule has not been released, there is no doubt that the North Korean nuclear issue will be a hot topic between Chinese President Xi Jinping and his U.S. counterpart Donald Trump.

At a press conference on March 30, Chinese spokesperson Lu Kang announced that Chinese President Xi Jinping would visit U.S. President Donald Trump at his Mar-a-Lago property in Florida from April 6-7.

Physically, THAAD serves as an Iron Curtain to intercept incoming missiles from North Korea. Separate national security interests have supplanted Cold War ideology, but THAAD could influence competing alliances and block cooperation among the countries involved in the “Six Party Talks.”

Given the domestic pressures faced by the major players, especially the US, in the near future, we can only expect an extension of the current dilemma.