George Armstrong Custer and severely mauled six others. Expecting a repeat of the Battle of Washita River, Custer ignored contrary intelligence or did not seek it out. In the 1879 Battle of Isandlwana, during the Anglo-Zulu War, a Zulu army wiped out a British army equipped with the most advanced weapons and tactics of the age. This victory at Isandlwana led a previously unengaged Zulus unit, Undi Corps under Prince Dabulamanzi kaMpande, to believe they would easily wipe out the British defenders in the Battle of Rorke's Drift with ferocity and sheer numbers and so attacked the location in violation of orders from King Cetshwayo kaMpande. Instead, the British, who used sensible tactics and concentrated their firepower as much as possible, won the battle and killed approximately 370 Zulu men. 20th century The battles of Cer and Kolubara during the First World War were considered disastrous defeats for the Austro-Hungarian Monarchy, whose overconfidence and underestimation of the Serbian Army eventually led to a two-year delay in the Serbian Campaign. The Battle of Pingxingguan during the Second Sino-Japanese War between Japan and China. After a series of easy victories against their opponents, the overconfident Japanese failed to take elementary precautions. Italy's entry in WW2 (1940) followed a series of victories in Libya (1922-1932), Ethiopia (1935-1936), Spain (1936-1939), and Albania (1939), which gave the Fascist regime the illusion of being able to win a global war against Britain. The catastrophic decision by Hitler to invade the Soviet Union in 1941 underestimated Soviet military resilience and counted on the success of the tactics used in previous campaigns, such as the Invasion of Poland and the Battle of France. Confident of victory, the Germans did not count on getting caught in a Russian winter or rasputitsa (mud season). As a result, the German offensive in the Soviet Union was halted on December 5, 1941. Japan's decision to attack Pearl Harbor on December 7, 1941. This followed wins in the First Sino-Japanese War, the Russo-Japanese War and the First World War, and early victories during the Second Sino-Japanese War. As it turned out, the attack appeared tactically successful, but was strategically disastrous with the US Pacific Fleet damaged to a relatively superficial degree, with its carrier groups out at sea while vital shore base facilities were ignored in the attack such as its fuel storage, whose destruction could have crippled fleet operations for months by