Rodrigo Duterte. (Bullit Marquez/AP)

Rodrigo “the Punisher” Duterte looks poised to be the Philippines’ next president, news that could have a major impact on the standoff in the South China Sea.

With unofficial tallies giving him a commanding lead, the tough-talking mayor asserted a win. “It’s with humility, extreme humility, that I accept this, the mandate of the people,” Duterte told Agence France-Presse, the French news agency, as the results came in.

But Duterte’s rise has been anything but humble and quiet, with the longtime mayor making international headlines for threatening to kill suspected criminals, joking about the rape and murder of a missionary, and promising to ride a Jet Ski to plant a Philippine flag on disputed reefs.

For his legions of fans in the Philippines, Duterte’s brash comments are as appealing as his promise to completely stamp out crime and corruption in just six months. They see him as a superman ready to challenge the status quo and willing to stand up for the little guy.

In the Philippines, presidential candidate and longtime Davao City mayor Rodrigo Duterte has stirred up contention with his brash, off-color statements on rape, extrajudicial killings and more. (Jenny Starrs/The Washington Post)

To his critics within and beyond the country, including in the United States, Duterte’s win is worrisome. They wonder how the man Human Rights Watch dubbed “the death squad mayor” will handle domestic and international policy, and are concerned about the return to the country of strongman politics.

One of the biggest unknowns is his China policy. “Foreign relations has been a major gap in Duterte’s published platform to date, and he and his team have yet to publicly define their approach to the South China Sea,” said Jay L. Batongbacal, director of the University of the Philippines’ Institute for Maritime Affairs and Law of the Sea.

China claims nearly all of the South China Sea as its “inherent” territory, based on maps that scoop into exclusive maritime economic zones claimed by the Philippines and others. In recent years, Beijing has built up islands across the area, adding civilian and military infrastructure to the outposts.

President Benigno Aquino III took a hard line with Beijing — once comparing China to Nazi Germany — and found himself frozen out.

With Chinese ships pressing farther south, Aquino moved to ramp up military cooperation with the United States. A defense pact upheld this year allows the U.S. military to build facilities at five Philippine bases, and more ships already are stopping by the former U.S. naval base at Subic Bay.

The deal, signed in the run-up to a ruling on the South China Sea by an international tribunal, will put more U.S. ships and troops in close proximity with Chinese forces, deepening the standoff. On Tuesday morning, the day after the election, a U.S. warship sailed close to the Chinese-occupied Fiery Cross Reef, Reuters reported.

It is unclear how Duterte plans to navigate the issue.

In February, he shocked many by suggesting he might be willing to soften the Philippines’ stance significantly — if Beijing is willing to pay.

The arrangement Duterte proposed would see the Chinese build railroads in his home region in return for his temporary silence on the South China Sea. “Build us a railway just like the one you built in Africa, and let’s set aside disagreements for a while,” he said.

Duterte later expressed skepticism about the Philippines’ case at the tribunal, questioning the worth of a ruling that China has said it won’t accept. “I have a similar position as China’s. I don’t believe in solving the conflict through an international tribunal,” he said.

He also expressed support for bilateral talks with Beijing and suggested the possibility of joint exploration of the area’s natural resources. “If negotiations will be in still waters in one or two years, I will talk to the Chinese,” he said.

Beijing has been calling for bilateral talks with its South China Sea neighbors, one by one. Critics in the Philippines and elsewhere argue that such an approach would give Beijing an unfair advantage over the smaller countries.

And then there was the Jet Ski pledge. “I will go there on my own with a Jet Ski, bringing along with me a flag and a pole, and once I disembark, I will plant the flag on the runway and tell the Chinese authorities, ‘Kill me,’ ” he said.

Of course, China would prefer less talk of heroism and heated nationalism. Though Beijing has been characteristically quiet on how it plans to engage Duterte, it is no doubt pleased by his apparent willingness to strike a deal.

On Tuesday, the English-language edition of Global Times, an organ of the ruling Communist Party of China, accused Manila and the media of “hyping” the political dimensions of the conflict at the expense of economic concerns.

An editorial in the same paper struck a similar tone, noting that the Philippine public “cares most about livelihoods, and nationalistic slogans cannot feed them.”

The piece blasted Aquino but expressed optimism about Duterte’s ability to change Manila’s “unscrupulous policy toward China.”

“If there is anything that can be changed by Duterte, it will be diplomacy,” it stated.

His challenge will be engaging China without alienating the United States.

If Duterte pushes ahead with joint development agreements or bilateral talks, he will need to tread carefully, said Richard Javad Heydarian, an assistant professor of political science at Manila’s De La Salle University.

“Given strong domestic anti-China sentiment and institutionalized security ties with America,” he said, “Duterte will have to keep Washington — a key strategic partner — on [his] side.”