The five causes of World War I were militarism, alliances, nationalism, imperialism, and assassination. With the rise of industry, European countries were producing more efficient military technologies than ever before. The Europeans were itching to use their new weapons because they had not been to war in a long time. Every country was aware that other countries were participating in weapon and troop proliferation, so this made them build up their militaries even more. European nations allied themselves with each other, creating a large and entangled web of alliances. The small/new European countries had prominent European powers on their sides, which caused any small, seemingly obsolete dispute to threaten major war. Nationalism arose