The USA just won the most medals in the 2020 Olympic Games in Tokyo, but whatevs I guess. They are building a high speed rail line in California between LA and SanFrancisco, and have been doing so since 2008. California High Speed Rail was a concept which had come in the 19th Century and left in the 20th, and the idea is stupid and is a legacy project of Governor Moonbeam. It's a complete shitshow that is already 80 billion dollars over budget, and the section they may actually complete in the undetermined future is between Merced and Bakersfield in rural California.

Japan was able to build high speed rail in the 1960s because B-29s of the USAAF completely removed all previous infrastructure and property lines in 1944 and 45. There was that issue of Japan being ruled by fascist maniacs who were turning everyone in Asia into slaves and were friends with the Nazi Germans. They had a clean slate to work from, just like many European cities after WW II, and we have property lines that stretch back centuries and they're respected, so they can't willy nilly run a track anywhere they like. They can build high speed rail in the PRC beause they can brush people away from the right of way like flies. People in the USA greatly prefer air and automobile travel to rail anyway.