What were main causes contributing to the outbreak of World War II?

The outbreak of World War II can primarily be attributed to unresolved issues from World War I and aggressive expansion. Following the conclusion of World War I, the Treaty of Versailles imposed harsh penalties and reparations on Germany, which resulted in significant economic turmoil and resentment among the German population. This dissatisfaction created fertile ground for the rise of extremist political ideologies, particularly the militaristic and nationalist regime led by Adolf Hitler.

As a result of these unresolved grievances, expansionist policies became prominent. Germany, under Hitler, sought to reclaim lost territories and expand its influence, leading to aggressive movements into neighboring countries such as Austria and Czechoslovakia. Additionally, Italy and Japan also pursued their own expansionist agendas during this period. This aggressive expansionism, coupled with the inability of the League of Nations to effectively address these issues or enforce peace, set the stage for a broader conflict that ultimately resulted in World War II.

The other options do not encapsulate the main contributing factors as clearly. Democratic reforms and economic stability do not relate to the causes, as many nations were dealing with instability post-World War I. Formation of global alliances and treaties, while relevant to the context of the war, were largely attempts to maintain peace rather than direct causes of the conflict.