Just days after France held a historic election, handing the presidency to Emmanuel Macron and a defeat to right-wing populist Marine Le Pen, South Koreans will go to the polls on Tuesday in an election equally as significant in a region facing a mounting nuclear crisis.

Only two candidates seem to have any chance of winning the Blue House to replace the impeached ex-president, Park Geun-hye. On the left, there’s Moon Jae-in, a former human rights lawyer and ex-South Korean army commando. From the center is Moon’s former colleague and moderate, Ahn Cheol-soo. So far, the smart money is on Moon.

Moon’s election might lead to a needed cleanup of South Korea’s political system which critics say is overly influenced by its hulking conglomerates known as chaebols. If he wins, Moon has vowed to vacate the palatial Blue House and work from central government offices. But Moon’s victory would also be viewed in two other Asian capitals — Beijing and Pyongyang — as evidence that their hard-line policies toward South Korea have succeeded. Moon has pledged, if he’s elected, to soften South Korea’s tough stance towards North Korea and seek closer ties with China, which is now, after the United States, South Korea’s biggest trading partner.

A warmer policy toward North Korea would constitute a victory for its young leader, Kim Jong Un. Since taking power almost five years ago, Kim has accelerated the pace of North Korea’s nuclear weapon and missile programs. And if Beijing emerges from the election with a South Korean government more amenable to China’s wishes than the Park administration, this would amount to a victory for hard-liners in Beijing’s government who have treated South Korea shabbily for more than a year.

Ever since July 2016, when the United States and South Korea announced an agreement to deploy the anti-missile system called Terminal High-Altitude Area Defense (THAAD) to South Korea and Japan to provide cover from North Korean missiles, South Korea has been under increasing pressure from China to kill the deal. The Chinese slapped sanctions on South Korean businesses in China. Chinese authorities shut 87 of 99 Lotte supermarkets there. They also banned most tourist travel to South Korea and, across South Korea, businesses that catered to the millions of Chinese who visit South Korea annually have closed. On March 20, South Korea complained to the World Trade Organization that China’s sanctions violated the terms of Beijing’s trade agreements with Seoul.

Chinese officials have insisted that the United States is using North Korea’s nuclear program as a ploy to deploy THAAD. They claim that the real goal is to use THAAD’s radar system to weaken China’s nuclear deterrence capability because the system could quickly detect Chinese missile launches and signal U.S. missile defense batteries elsewhere. U.S. officials have countered that THAAD’s radar does not extend into China.

In March, China’s semi-official Global Times newspaper editorialized that China was completely justified in punishing South Korea for trying to defend itself against the menace of North Korean missiles. “Economic sanction is necessary and effective against Seoul,” the paper declared. It noted that South Korea’s economy is smaller than that of China’s and that South Korea is more dependent on China for trade than China is on South Korea. It predicted that “tough economic sanctions … may then exert some influence on the country’s political arena.”

It is not exactly clear what Moon would do should he win. Early, on the campaign trail, he vowed to scrap THAAD’s deployment. But as China’s pressure mounted, Moon was forced to reconsider; he accused China of applying what he called “excessive pressure” on Seoul and declared that the decision to deploy THAAD was none of China’s business. That said, when President Trump announced in April that the United States would force South Korea to pay for the antimissile system, it reopened the debate anew.

In the end, if China’s tough tactics with Seoul succeed in convincing South Korea to re-think the THAAD deployment, it does not bode well for the rest of Asia. Success with the South Koreans could embolden China to try similar tactics with Japan, Vietnam and perhaps even Australia. They say that you catch more flies with honey than with vinegar. But in East Asia, the Chinese could be forgiven for thinking that the opposite is true.