Watch Online Free HD Solarmovies. One of the keys to Germany's early victories during World War II was the Panzer tanks. Although their heavier counterparts historically have received more attention, the Nazis' light tanks -- the Panzer I and II -- nonetheless played an invaluable role. This documentary zeros in on the smaller, more nimble machines, which, despite their light weight and thin armor, were a critical component in the defeats of Poland, France, Yugoslavia and Greece.