World War II was fought because Hitler wanted to expand Germany and takeover the world for his master race. The Japanese leaders had much the same idea. The major countries involved were England, Germany, the United States, Japan, and the Soviet Union. There were other countries, such as Italy, Poland, and France.
About 50 nations fought in WW2 but basically the whole world was involved.
Woodrow Wilson played a huge role in determining if and when America would get involved in World War I. He also fought for the League of Nations to help avert another World War which won him the 1919 Nobel Peace Prize.
960 million people fought or served in World War 1. 1,963,208,400 people served or fought in World War 2. These figures include all nations involved, all the armed forces and includes women who served.
The key nations involved in the fighting were the United States, the Soviet Union, Great Britain, Germany, Japan, and Italy. Nations including Poland and France fought in the war but were overrun. The war raged across several other nations.
23 nations.
Australia fought in wars with Britain because Britain OWNED Australia until after World War 2. The wars after that in which they fought together with the Brits were when they were doing United Nations military functions. They have not fought in any war because OF their desire to support Britain but because they are allies together in the United Nations.
World War I was so named in retrospect with reference to World War II. At the time that World War I was being fought, it was simply known as "the Great War". These two wars were termed "World Wars" because they involved so many more countries than had every been part of any previous war. In the past wars were usually fought between two factions within a nation or a couple of nations or perhaps 2 or three nations allied against 2 or 3 other nations. In these wars, many, many nations were allied on each side and the battle fronts reached across the continent and out into the oceans. In the case of WW II, the battle was being fought in Europe, Africa, Asia, the Atlantic, and the Pacific - truly a world-wide war.
the USSR and the US
The United States fought against the United Nations during World War I and then fought Canada and Emperor Palpatine's droid army after nuking the UN headquarters in New York. The US won.
The USSR, and the United States of America.
Nearly all the major nations were involved in World War 2.
Britain, Australia and Germany.