Until Japan joined the war, we mainly had British aircraft, the old colonial thing you know.
After Japan, we could use the "lend/Lease" from the USA.
After the war, we were, at first, still British [it helped to sell our butter,] but now are mainly USA.
In the 1970/80's we picked up a small trainer made in Australia, by a lawnmower manufacturer, changed it a little, and then sold them back to Australia.
Now, they are using them to teach British Pilots how to fly, using them.