His many outbursts against the United States, in fact, look genuine, rooted in a century of Philippine nationalism and mistrust. Duterte was schooled in anti-Americanism from an early age. His grandmother, a Muslim, taught him that the United States was guilty of grave crimes during its colonization of the Philippines. To this day, he refers to the 1906 massacre of the Muslim Moros and believes Washington has not atoned for this particular instance of brutality or, more generally, the torture of Filipinos and the subjugation of his country. To make matters worse, Duterte then learned politics in university in the 1960s from Jose Maria Sison, the founder of the Communist Party of the Philippines. The president now proudly calls himself a leftist.
All these factors mean that America, in Duterte’s eyes, can never do anything right.
The United States does not take sides on the many South China Sea territorial disputes—China’s claims also conflict with those of Taiwan, Malaysia, Brunei, Indonesia and Vietnam—but Washington does insist on peaceful resolution. Beijing’s actions, however, have been anything but peaceful. For instance, it seized Mischief Reef in a series of acts beginning in 1994. The feature is far closer to the Philippines than other claimants—Hanoi and Taipei as well as Beijing—but Washington did nothing to reverse the Chinese action
And as a “senior U.S. military official” told the Washington Post in 2012,
I don’t think that we’d allow the U.S. to get dragged into a conflict over fish or over a rock. Having allies that we have defense treaties with, not allowing them to drag us into a situation over a rock dispute, is something I think we’re pretty all well-aligned on.
In short, the United States did nothing to hold China accountable for its deception
The Chinese knew the United States had remained idle when they grabbed the much-closer Scarborough, even though they had brazenly repudiated the agreement Washington had brokered with themselves and Manila.
Washington’s abandonment of Manila was especially evident when an arbitral panel in The Hague handed down its landmark decision in Philippines v. China last July, invalidating the nine-dash line and ruling against China on almost all its positions.
Secretary of State John Kerry did say China should accept the award, but he spoke without seriousness. He did not pressure Beijing to honor its obligation to accept the ruling, but instead leaned on Manila to bargain with China, backing the Chinese position on starting talks. Kerry’s posture was indefensible.
Duterte, among others, has noticed Washington’s reluctance to protect his beleaguered country. “America did nothing,” he said in October 2015, referring to China’s reclamation activity
Duterte’s close friend and cabinet-level peace adviser, describing the president’s views. “The idea is that our allies are not going to go to war for us, so why should we align with them?”