Is there anything that would get the Americans to enter the war on the side of the Russians?
Or is this just too ASB?
Ouch. Not a lot of time between 1900 and the end of the war in 1905 for a POD.
OTOH, the US sent aid to Russia in WWI, and sent an expeditionary force at the end of WWI to fight against the communists. Teddy Roosevelt was involved in the peace process that ended the war.
The US had recently won the Spanish-American war and gained an increased role in the Pacific. The Philippine Insurrection was over. Up until 1904 the US Asiatic Fleet had at least a few armored cruisers.
Thinking and researching as I go here, I don't think it is ASB. Can't think of a good POD, though.
Perhaps if during the Philippine Insurrection the Japanese tried to slip some aid to the anti-US factions (hoping to gain control of the islands themselves in the long run) and got caught?