Philippine President Rodrigo Duterte has banned all foreign scientific research off the country's Pacific coast and told the navy to chase away unauthorized vessels, despite earlier allowing Chinese oceanographers to operate there.
There was no clear explanation for the about-face by the mercurial Duterte, who has cultivated warm ties with China — ostensibly to attract loans and investments and lessen Manila's dependence on the United States.
The particular area of concern is Benham Rise, which the United Nations in 2012 declared part of the Philippines' continental shelf. Manila last year renamed it "Philippine Rise."