Both of them.
Many
There's only been two world wars in the history of man.
There have been two World Wars, and Italy has been involved directly in both of them.
There has only been 2 world wars.
The United States has fought in World War One and World War Two, the only two world wars so far.
No, the United States has not been in three world wars.
How many? You think there has been MORE than two world wars? And in both cases, the US was involved. Honestly, some people.
These wars are known as World Wars because many countries of the world fought in the war
UN, NATO and EU
there have been many wars.
Only two wars to date are known as world wars.
Isolationism