World War 1 was caused by several instances over time. The assassination of Franz Ferdinand was just the final step of the start of the war. The German's had been wanting to take more land from the surrounding countries in Europe for a long period of time. When the Siberians needed back up because of the assassination it was just what Germany had been looking for to begin their land grab. There was more than one instance that led to World War 1, many of them involving Germany.