In this activity, you will learn about wars fought for protection.

At this same time, nationalism developed a strong sense of pride in one's own nation. These two factors led to a growth in militarism, and nations built strong armies and stores of weapons so they could protect themselves and their territories.

Nations also began to group together in military alliances. For these reasons, by the beginning of the 1900s, the situation in Europe was quite unstable.

Two major alliances, one led by Germany and the other by Great Britain, were against each other. The countries in both alliances had massive amounts of military personnel and large supplies of weapons. Several conflicts involving two or more of the member nations of these alliances occurred in both northern Africa and eastern Europe. When members of these alliances began to protect the territories of other members, World War I began in 1914. British Commonwealth nations, including Canada, entered the war because they believed that their mother country, Great Britain, needed help to protect herself. This was called a world war because it was the first war that involved many nations.

It was initially called the Great War, but when a second world war occurred about 20 years later, the first war became known as World War I or the First World War.

In 1918, the First World War ended with the defeat of Germany. Severe punishments and restrictions were inflicted on that nation to try to ensure Germany would not rise to power again. The treaty that ended the war was called the Treaty of Versailles.

Unfortunately, this created the circumstances for Adolph Hitler to use the strong German ultranationalism to take control. After Hitler's imperialistic expansion into several European nations, Great Britain and her allies believed that Hitler might invade their nations. World War II began as nations fought to protect themselves and each other from an aggressor.

You will learn more about Canada's involvement in both world wars in upcoming lessons.
   

Obviously, the two world wars were the main conflicts of the 20th century, but many other smaller yet significant battles occurred on all continents except Australia. Many of these occurred within a nation, as groups struggled to gain power. Sometimes, the war was a revolution against a monarch, government, or leader that mistreated its citizens.

 At other times, it was a civil war as groups within a nation battled each other to take control. The practice of expanding one's territory continued to cause conflict in some regions. If a conflict involved a colony of one of the imperial nations, that nation often intervened to ensure that the group supporting the interests of the imperial nation won. In Asia, both China and the Soviet Union fought wars against Japan as it expanded its territory to try to control all eastern Asia.