Explanation:
The start of WWI could not have been avoided.
At that time period (1914), all of Europe except for Switzerland and France were rule by Kings and Queens known as royal families. The general belief was these families were part of a higher class. They married within their class and in many cases, the rulers were related by blood. In effect they were ordained by God to rule their people.
Besides being the rulers of their countries, they were very wealthy. At the time there were a complex set of alliances where if one kingdom was attacked, its allies would rush to its aid.
The various royal families believed in having a strong military. The military served two purposes. First, would be as a strong defense and second would be as a supreme powerful offensive force.
In the case of naval power, the expansion of both numbers and sizes of the ships was a major factor. Great Britian at the time had the largest most powerful navy in the world.
After the Spanish-American War in 1898, the US entered the world class of power. At the time it added Hawaii, the Philippines and Cuba. It increased the size of its navy.
Great Britian created the new dreadnought class of warships which raised the bar of what navies would need. Each of the major powers was forced to build bigger and faster ships. This was an arms race.
Besides naval strength, each super power developed new rifles, ammunition, artillery and larger standing armies. As their militaries increased, each king, queen and emperor had their egos stroked and their national pride increased.
After 1905 when Japan defeated the Russian Navy, Japan entered the mix.
The countries that were occupied by super power nations had also felt extreme nbn e national pride. Serbia was one of those nations. At the time it was part of the Austria Hugarian Empire and it wanted its independence. In August of 1914, Archduke Ferdinand visited Serbia. The underground anarchist organiation in Serbia plotted his assassination. Having survived the first attempt on his life, perhaps he felt immune to their attacked as he was protected by God. He continued his tour and was shot and killed by Mr. Percip a member of the Black Hand.
As the future Emperor of the Austia Hungarian Empire, his assasination had to be avenged. The King of Serbia was held responsible for the assassination and issued a set of humiliating demands which were rejected by the Serbian King. He in turn contacted the Tzar of Russia to verify their alliance. When Serbia was attacked by Austria, Russia attacked Austria and all of the alliances fell into place.
With all of the military build up that was going on at the time, each country's leaders felt obligated to use their military forces.
