Answer:
1. Alliances and politics:
Over the 19th century, rival power of Europe formed alliances. Great British, France and Russia formed the tripple Entents. Political inability and competition threatened those alliance.
(italy for example eventually entered Worldwar war one in opposition to Germany and Austria Hungary)
2. Europe ready for war:
In 1914 the situation in Europe was tense. Secret alliance, internal politics , and the desire to grow Empires had build up disturbence and dislike between many of the European powers.