What is the most important cause of WWI?

The Great War, even though it has been regarded to have been caused by many factors like militarism, nationalism and secret alliances, I believe that the main cause was the countries’ desire for expansionism, imperialism. Imperialism is a cause of war that triggered all the other factors and therefore I believe it is considered the most important cause of World War I.
Imperialism is a form of colonization, but concerns political and economical matters rather than just the expansion of a territory. The historical significance of it is that powerful countries established imperialism by expanding their economy and trade also affecting Third World countries. It occurred in 1870-1880 in Europe.
The Great powers of Europe began to need more than just their own land, not for land expansionism only but for imperialism. Countries needed to gain access to weaker countries in order to have trading access, therefore expanding their economy. For example Britain’s desire to imperialize Africa since Africa was easy to be manipulated due to being so poor. Britain invested in Africa’s businesses and factories and took up most of their money, therefore taking advantage of Africa. This lead to industrialization, which is a significant happening in history because to due to industrialization, technology expanded. The fact that technology expanded is not necessarily the best thing that could have happened in a time where the powers of Europe were already competing with each other, for example when France and Britain had tensions between them because France also wanted a piece of Africa.
Industrialization came with its competitive factors which lead to nationalism. The Dreadnaught is a great example of nationalism. The Dreadnaught is a creation of Britain after the industrial revolution; new machinery was made and therefore created a massive metal boat that could carry hundreds of people and goods. This triggered tensions between Germany because Germany was afraid that Britain would gain trading access in more countries, get more goods and therefore become more powerful. However, Britain also felt threatened by Germany due to her rapid growth of the navy, when admiral Tirpitz was the head of the German nave, since Britain was known for having the strongest navy in Europe. This obviously caused tensions between the two countries. Another example of nationalism is the Franco-Prussian war when France lost to Prussia (Germany) and gave up Alsace and Lorraine. France’s loss never stopped the tensions between Germany and France swore to get the two territories back.
Another cause of the Great War is militarism and alliances between countries. Militarism was triggered by nationalism and this triggered the creation of alliances. However, alliances would never be made if countries didn’t have the reassurance that their allies were powerful and their power came from imperialism. An example of military action is the French “Plan 17”. This plan was made for the purpose of getting Alsace and Lorraine back and this included having French troops surrounding the boarders of the two territories. This plan caused the creation of another plan the German “Von Schlieffen” plan. The purpose of this German plan to defeat France in order for Germany to keep Alsace and Lorraine and to do that, the Von Schlieffen plan stated that Germany would have to pass through Belgium in order not to come across the French. Belgium was a neutral country and the fact that Germany invaded the neutral country caused tensions between Britain which then became allied to France and Russia and eventually lead to war. The war inevitable since alliances had already been created and therefore divided up Europe in two- the Triple Alliance (Germany, Austria-Hungary and later on Italy) and the Triple Entente (France, Russia and Britain).
The Great War, even though it has been regarded to have been caused by many factors like militarism, nationalism and secret alliances, I believe that the main cause was the countries’ desire for expansionism, imperialism. If the desire for expansionism hadn’t existed then the other causes would have never been triggered. I do not believe that war was inevitable if the countries stayed neutral; however the countries’ competitive acts did lead to tensions between them and made war inevitable.