How was the arms race an important cause of World War I?

There were many factors that led to the start of World War I. One of those factors was militarism, the building up the military. King Wilhelm II of Germany wanted to have a strong military. As a result, he began to build up Germany’s army and navy.

Germany was interested in gaining colonies. Since there were few colonies available, other European countries feared Germany would use its military to attack them in order to take their colonies. This led these countries to build up their army and navy to provide more protection in case of attack. As other events unfolded in Europe prior to the start of World War I, the presence of larger and improved militaries in many European countries provided some comfort that each country could hold its own if a war did occur. With countries having their military power in place, there was less hesitancy to declare war.