What is it? An alliance is an agreement that is signed by two or more nations for political, military, or economic reasons.The system of alliances was one of the best known causes of WWI.
Summary: The system of alliances was one of the best known causes that led up to WWI. Some alliances that led up to WW1 that began in 1914 had many treaties but one was the was the treaty of London in 1839, between Belgium and Britain. But article 7 is important to the beginning to WW1. Britian must protect the neutrality of Belgium. They might have been excuses but in reaitly they really wanted to declare war on the other contries to keep the other countries in check for military purposes. Going forward to 1870 Germany was called Prussia which fought France in the Franco-Prussian war which resulted in Prussia winning, making Prussia a leading German state.