US primarily. Paying cold war allies to develop a patronage network of supporters. The corruption pressures of that is what creates the system. And it was the US that was primarily responsible for the original Marcos corruption, certainly not the Catholic Church. The duterte family is just playing the game the Marcos started.

It's a simple formula really. Foreign money for focusing on foreign interests over local ones delegitimizes a regime. The less legitimate it is, the more corrupt it must be with patronage networks and graft to maintain power. And so it goes.