Imperialism and Nationalism + the MAIN causes of WW1
There are both simpler and more complicated analyses that can be made of the cause of WW1 but MAIN: Militarism, Alliances, Imperialism and Nationalism is certainly one that helps us make sense of a very complicated story. But I don’t think the best explanation is made if you take each of the factors in the order that they appear in the acronym. The acronym is good for remembering the different factors, but not, in my opinion, in showing how the factors link; and showing how different factors link is one of the paths to writing very good history.
I would recommend that you think of Imperialism and Nationalism first, and that you think of them together. For it is the clash of imperial powers – Russia, Austria-Hungary and the Ottoman Empire – with the Balkan states, particularly Serbia, as they sought independence, that is the central factor in explaining WW1. After all, where was Archduke Ferdinand, the heir to the imperial Austro-Hungarian throne, assassinated? In Sarajevo, the Bosnian capital, and Serbia strongly felt that Bosnia should be a part of a greater Serbia. Ferdinand and his wife, Sophia, were killed by a young Bosnian nationalist, a member of the Black Hand group, who had been helped by Serbian officials as well as members of the Serbian army. Whilst the reason for Archduke Ferdinand’s visit to Sarajevo was to observe military manoeuvres; manoeuvres with Serbia as their likely target.
And largely because of the unfolding clash between imperialism and nationalism in the Balkans (and though there were imperialist clashes in Africa, they were not such a key factor), alliances were formed, and as the clashes in the Balkans only grew more heated, armies grew in size and military plans in case of war were developed, notably by Germany but also Russia and France.
There were imperial clashes in Africa but, the Moroccan crises apart, they never looked likely to cause a major European war, and those crises in Morocco were easily avoidable. Whereas a final confrontation in the Balkans seemed highly likely, and the alliances and the military planning, made the Balkans the most likely cause of a major European war. The Dual Alliance between Austria-Hungary and Germany, and which targeted Russia, was made after the first Balkan crisis and led to a chain reaction that left Europe divided into two highly suspicious, and well-armed, camps.
So, MAIN works for you but it works best if you rejig the order in which you use it.
But history is always ultimately about individuals and you might want to add another letter to the acronym to make: MAINS. The “S” stands for ‘significant individuals’. At the end of the day, the decisions that led to war were made by a very small group of people. The most significant individuals were Kaiser Wilhelm of Germany, Tsar Nicholas of Russia and Emperor Franz Joseph of Austria-Hungary, though they had political advisors and military chiefs advising them too. It was their decisions over the long term that continuously built up the tension in Europe and which during the July Crisis ultimately drove Europe to war.