President Rodrigo Duterte’s official visit to Japan went according to plan, and we can join his hosts in breathing a sigh of collective relief. The cancellation of his courtesy call on Emperor Akihito could not be helped; the emperor’s uncle had died at the age of 100, and the imperial family was in mourning. But the President responded graciously to the Japanese protocol officer’s request not to push through with the appointment. “I respect that. I would ask for the same request if I were in his shoes.”

Indeed, the President’s visit abounded in grace notes. He repeatedly emphasized “the rule of law” as a standard by which international disputes—including contentious controversies with China over the South China Sea—should be resolved. “The Philippines will continue to work closely with Japan on issues of common concern in the region, and uphold the shared values of democracy … the rule of law and peaceful settlement of the disputes, including the South China Sea,” he said after meeting with Prime Minister Shinzo Abe. This kind of language was an improvement over great-power rationalizations that have sometimes been used to justify closer ties with China.

He sought to assure the Japanese that his state visit to China the previous week was about trade and commerce, not military aid or partnership. “You know I went to China for a visit. And I would like to assure you that all there was was economics. We did not talk about arms. We avoided talking about alliances,” he told a forum for Japanese businessmen.

He pledged that the Philippines will “not abandon Japan in our partnership and security matters, given the common belief that our conflicts and problems with other nations must be resolved peacefully, in accordance with international law.” This was a remarkable statement, not only because of its message, but also because of the role the messenger assumed: Usually, it is the larger nation, with the bigger economy and army, who makes promises about not abandoning a neighbor.

Touting the two countries’ “solid, strategic partnership,” Mr. Duterte also described Japan as “a special friend who is closer than a brother.”

Even his continuing broadsides against the United States, Japan’s principal ally, used smaller-caliber language. There were no personal insults or prolonged history lectures, which would have been inflammatory in decorous Japan, just the deliberate rhetoric of a political leader who had, finally, calculated the odds and done the political arithmetic. “I have declared that I will pursue an independent foreign policy. I want, maybe in the next two years, my country free of the presence of foreign military troops. I want them out,” he said, referring to American forces in the Philippines under the Visiting Forces Agreement.

He added: “And if I have to revise or abrogate agreements, executive agreements, this shall be the last maneuver [and] war games between the United States and the Philippine military.”

We suppose that the President’s Japanese hosts had already factored his out-with-America policy direction into the visit. That change in policy remains very controversial in the Philippines, for the simple reason that Mr. Duterte did not campaign on it; the electorate remains heavily pro-American, and his talk of “separation” has roiled the waters. But Japan, the world’s third-largest economy, is committed to its American alliance and continues to host US bases and at least 50,000 US soldiers.

It must have expected the President to say what he said about the Americans—and still made the case, privately, for continued US military presence in the region.

In this, and in the matter of the Duterte administration’s war on drugs, Prime Minister Abe tried to strike a balance. He did not raise human rights issues over the killings; he only offered assistance for the rehabilitation of drug users. He heard the President on the Americans, but did not say anything in public. This important relationship bears close watch, over the next several months.