National Security Advisor John Bolton is scheduled to visit Japan and South Korea next week, a trip seen in both countries as President Donald Trump’s effort to mediate the escalating feud between the two vital U.S. allies as nuclear diplomacy with North Korea resumes.

Japan and South Korea are fighting over wounds that never really healed after World War II, a period during which Imperial Japan occupied South Korea and used many of its people for forced labor and prostitution.

The current crisis ignited when Japan accused South Korea of allowing banned materials into North Korea and imposed export controls on materials vital to high-tech manufacturing. The conflict could well have repercussions for industry around the world, including the United States.

South Koreans are beginning to boycott Japanese goods to express their anger as provocations and snubs fly back and forth between Seoul and Tokyo.

One elderly South Korean man may have gone even further on Friday and burned himself to death in his car in front of the Japanese embassy in Seoul, possibly because he was angry about the trade war. The Korea Times reported the man’s motive is not known with certainty, but his father-in-law was a victim of forced labor during the Japanese occupation.

The Korea Times noted on Friday that reports of Bolton’s visit and his exact schedule are somewhat speculative. Speculation commenced immediately in both Japan and South Korea, as the Korea Times reported:

Kim Hyun-wook, a professor at the Korea National Diplomatic Academy, said on Friday that Bolton’s visit could be a signal that the U.S. will take a more active role in meditating the worsening trade row. “Because Bolton has taken a hardline stance toward China, he values the trilateral alliance among the U.S., South Korea and Japan,” Kim said. “As the ongoing conflict between Seoul and Tokyo does not seem as it will be settled in the near future, even after Stilwell’s visit to South Korea, Bolton is likely to address the issue again by visiting the two countries,” he added. He was referring to the recent visit to South Korea by David Stillwell, the new assistant secretary of state for East Asian and Pacific affairs. Stillwell visited Seoul from Tuesday to Thursday. Park Won-gon, an international relations professor at Handong Global University, said the U.S. was trying to prevent the trade conflict from snowballing into a bigger issue. “Bolton is likely to tell the Japanese side not to take further hostile measures toward South Korea, while telling the South Korean side to discuss the forced labor issue with Japan, without putting any conditions,” Park said.

In addition to helping resolve the Japan-South Korea dispute, the Korea Times expected Bolton to discuss U.S. plans for a multinational force to ensure maritime safety in the Persian Gulf region as the threat from Iran and its proxies grows more alarming.

Some Japanese media viewed the Persian Gulf situation as the top item on Bolton’s agenda. The Mainichi, for example, could think of no other reason why President Trump’s national security adviser would pay a visit to Tokyo.

NHK World, on the other hand, quoted sources in the U.S. and South Korea who thought Bolton would use his trip to encourage Japan and South Korea to “sit for dialogue and resolve the issues.”

The Korea Herald reported on Thursday that Bolton was originally planning to visit Tokyo only, but South Korean officials lobbied for him to come to Seoul as well. According to this report, Bolton wants to convince South Korea to participate in the multinational security force Washington envisions for the Persian Gulf.