The First World War.
World War I
The only country to have used nuclear warfare in history is the USA
how was the fist pistol used in warfare it was used in close combat if nessasary
Trench Warfare
There are no records to determine which country first used ships to trade with.
During World War Two, the first mechanized warfare was used in fighting. This was in the form of tanks and airplanes.
Trench warfare.
they used trench warfare and used powerful machineguns
Finland
China used paper as currency in the world for the first time.
Trench warfare was mostly used, and planes were used to locate enemy positions