Meet the Tanks That Won World War II (And Tore Up Europe) These war-winning weapons stemmed Nazi attacks from the gates of Moscow to Tunisia and the Battle of the Bulge, and swarmed in their thousands to surround and eliminate the Wehrmacht’s ground forces in campaign such Stalingrad, Operation Cobra and the Bagration offensive. Here's What You Need to Remember: The key conclusion is that the Allied tanks were engineered for mass production and to handle routine battlefield tasks well, rather than being over-engineered to survive the heaviest guns or penetrate the thickest armor. Upgrades introduced in 1944 gradually helped address undeniable shortcomings in armor penetration when facing the smaller force of German heavy tanks.