WI Japan attacked the Philipines in 1905?
They decide to focus south instead of north. I don't know why they do it, it's WI. You tell me why they do what they do, or just accept something pointless occured.
I think you should look at the Anglo-Japanese Pact. I believe that there was a clause that the British would remain neutral in the event of a war between the United States and Japan. Their main worry is Canada.
I might be able to help you out with a motive.
First POD
President William Taft 1905
I would suggest not having Teddy Roosevelt in the Whitehouse, as he was quite realistic with Japan by signing the Taft-Katsura Agreement of 1905. So lets make the first POD William Howard Taft entering the Whitehouse pre 1905. His and Secretary of State Knox's “Dollar Diplomacy” and fear of Japanese Expansionism are a good way to get the Japanese Government angry. Them been nearly racist over stopping Japanese Migration to the United States could be a potential power keg for war.
If I have my dates in the right order, Jackie Fischer is just becoming the first sea lord at the time. So the Royal navy is going to be going through a shift from concentration in foreign stations to home waters and a massive scrapping program of obsolescent ships. Just wanted to add that for consideration.
Significant problem there: Taft was TR's protege. With his judicial temperament, there was no chance he would have run for president on his own without TR providing both encouragement and endorsement. That's assuming that he MIGHT have been the '04 GOP nominee, which is unlikely: that would mean in turn that either McKinley served his second full term and was not assassinated, or that McKinley's VP was not interested in serving a term in his own right upon succession. In the former case, that means two Ohioans in a row getting the GOP nomination (which smacks of Reconstruction days, and the mediocrities from Ohio that the GOP nominated in the 1870s and 1880s); in the latter case, it's hard to imagine who might have been McKinley's running mate, particularly given the machinations of Mark Hanna et. al. in an attempt to sidetrack TR once and for all.
Add to that Japan's ongoing involvement in a war with Russia starting in 1904 and you're edging into ASB territory to have Japan fighting another major power.