Late assessments from the Abwehr contributed to military overconfidence and their reporting mechanism said nothing of the massive mobilization capability of the Soviet Union, an oversight that arguably contributed to the German defeat since time-tables were so important for German success. The German Army's failure to reach its objectives in short order proved pivotal; once winter came, improperly outfitted German forces suffered when supplies did not reach them.[48][lower-alpha 13][lower-alpha 14] Overestimating their capabilities and trusting their own assessments too much, as well as underestimating their enemies (especially the Soviets and the Americans),[lower-alpha 15] atop long-standing traditions of unconditional obedience, comprised a historically central weakness in the German system, according to historian Klaus Fischer.[51]