It was not simply two countries, but it was the Axis and Allied Powers.
Britain and America
Like anybody cares what countries world war1 was fought am I right?
USA & Borneo,
They fought the Germans, Japanese, and Italy
Some countries have accurace (or as accurate as possible) records of who fought in their forces in World War I; but some countries for various reasons have little or no records of this information.
Germany
germany, italy, and japan
germany and russia
The United States
germany
yes, in some countries such as Russia...............
Japan and Germany .