In regards to the Japanese, Teddy Roosevelt encouraged the Japanese to conquer Korea. He thought the world would be a better place if the Japs were in charge of Asia.
They also copied a lot from America. The Chinese and Koreans were still basically factions at war with each other at this time. Ditto for the Filipinos. So his thinking was based on reality.
Remember also that after our reluctant acquisition of the Philippines at the end of the Spanish American War, Democrats wanted to do what they've wanted to do in most wars since-- bug out and leave the consequences for the locals. The Philippines was not ready for independence and had many factions at war. It would have been a long a bloody civil war with the strong possibility of a rump Muslim state emerging.
McKinley sent William Howard Taft to be colonial governor and he did such a great job, that the vast majority of the Filipinos genuinely loved him by the time the last of the independence factions had collapsed. Taft also worked tirelessly to lower tariffs so the Philippines would have something to sell to the United States, mostly footwear and clothing, as it turned out.
Unfortunately, this and the rift with TR during his four year presidency, paved the way for the misrule of Woodrow Wilson and the income tax.