In the case of Iron Stars, this is entirely true - this universe takes place in an alternate World War I, in which the Martian Invasion actually happened, the ether is all-pervasive, and Cavorite is a reality.
But what alternate space WWI is complete without the United States of America, in the form of the United States Ether Navy?
Though the Americans are a lil' too... late for the Space Race party, the USEN has a truckload of technological surprises for the Entete-Central space theater of war, namely Carriers and Fighters, which the Japanese Uchuu Kaigun has also developed to be equal hostiles.
Anyone asking why are the USEN ships painted black is because I was inspired by the Black Ships (黒船 kurofune) that arrived in Japan in the 15th and 19th Centuries. The USEN decided to also paint their etherships black, just to give the Japanese nightmares to remember their party if they happen to cross paths with each other...