The Second World War shared some similarities with the First World War, for example, extreme nationalism, alliance system and armament race.
To begin with, extreme nationalism was the major cause of the First World War. Similarly, it was also found in the cause of the Second World War. In Germany, Nazism emphasized that Germany should fight for their living space as found in the Nazi Bible, My Struggle, so Hitler promoted Pan- Germanism. That resembled what Kaiser William II promoted before the First World War. Besides, Italy could not get what she wanted after First World War and thus she became a totalitarian state. Later, Mussolini always emphasized to revive the past glory of Roman Empire. Both Germany and Italy encouraged foreign expansionist policy and they even started the Second World War due to the revengeful movement. Consequently, extreme nationalism worsened the international relationship and brought the world into another world war.
Second, alliance system was a factor which was found in both world wars. Alliance system played a significant role in leading to the outbreak of First World War. During the inter-war period, several totalitarian states formed different military alliances. Nazi Germany formed Berlin- Rome Axis with Fascist Italy to fight in Spanish Civil War in 1936. Later, this alliance became a military alliance as The Pact of Steel in 1939. By forming these alliances, the totalitarian states grew stronger and more aggressive, so they started their invasions and extend their influence. Therefore, alliance system brought the world into the outbreak of the Second World War.
Third, armament race was also a reason