Tensions leading up to WW2 can be traced to

Many people would trace the build-up of tensions to WW2 to the outcome of World War I. Following the First World War, Allied Powers forced the Central Powers (such as Germany) to pay high levels of reparations resulting in economic depression in those nations. The economic turmoil in Germany, for instance, enabled the rise of fringe parties such as the Nazi Party under Adolph Hitler who campaigned and stoked animosity against Allied Powers for his own political gain.