The Allied Powers were a military alliance, so the term is quite straightforward. However, you might still ask why the opposing military alliance between Germany, Austria, and Italy, was not referred to as allied powers. We tend to think of alliance as a good thing, so when we are in an alliance we are the allies; when our enemies are in an alliance, it is more of an axis of evil kind of thing. In WW II people talked about the Berlin-Rome-Tokyo Axis. It should be noted that Japan was not formally allied to Nazi Germany, although it became a kind of alliance in that both Japan and Nazi Germany were at war with the US.
Nazi, allies
Axix and Allies
The Allies and the Axis.
The enemy.
The Allies
There were called the Allied Force, The Allies, an ally or the alliance.
The Allied Forces in World War 2 had more allies than the Axis did.
Cold War
Britan was one of New Zealand's allies in world war 2.
They were called allies. The USA, USSR and United Kingdom were called the BIG THREE.
World War 2 was of two alliances. The Axis, and the Allies. Great Britain and U.S.A were on the Allies side.
The US and the Allies won World War 2.