The US doesn't invest anything into them. That's not how swimming works in the US. Swimmers train in clubs which receive no money from the government. Sure they spend about a month at the Olympic training camp but most all the swimmers bring their own coaches and do 99% of their training with the respective clubs and/or universities.
I know that too. I even spent a whole intercontinental flight talking to a Big Ten US swim team coach. He was on his way to scout talents in Europe.
However, in most of the world, we refer to just the country. For instance, in USA you say Team USA won gold about the USA in the olympics. Meanwhile in rest of the world, you probably just say USA won gold.
A big difference between USA and rest of the world, is that the athletes in USA, have basically been "rockstars" since they went to junior high.
In most other countries, a swimmer is only / possibly a rockstars once he wins olympic gold.