The U.S. M4 Sherman was the primary tank used in WWII, but was outmatched by their German counterparts in armor and firepower and was eventually replaced by the M18 Hellcat.
The German Panzers (Panzerkampfwagen or PKWIII and PKWIV) gave the Germans an early advantage in WWII with its thicker armor and larger caliber gun.
The Russian T34 is considered to have the best balance between firepower, mobility, and ruggedness. Its 76mm gun was best in its class, it was more agile than its PZ counterparts, and its sloped armor served as effective protection against most anti-tank weapons.
German campaign in Scandinavia, 1940
The bombing of Rotterdam in 1940 left a psychological impact on civilians.
German invasion of France, 1940 (Rotterdam is just north of Dordrecht)
French soldiers retreat from Dunkirk to England as the Germans advance with the "pincer" movement.
The Lend-Lease Act clearly demonstrates that the United States was not neutral before declaring war.
Japan's WWII war objectives
The Anti-Comintern Pact signed between Germany, Italy, Japan, and Spain in 1936 forced Germany to declare war on the United States when Japan attacked Pearl Harbor.
The MXY-7 Ohka "Cherry Blossom" would release from a larger bomber and was capable of delivering a payload of its own.
The D4Y4 Special Strike bomber carried a larger payload but had no mechanism for delivering it.
Kamikaze pilots would either approach from above 20,000 feet to avoid radar detection or below 500 feet to avoid anti-aircraft fire.
Maginot Line defenses
Maginot Line
Spitfires vs. Stukas
Battle for Britain
Battle for the Atlantic
The ASDIC was effective at detecting submerged U-boats, but was ineffective at sea level.
Operation Barbarossa
Battle of Stalingrad - German commander Paulus is surrounded by Soviet commander Zhukov
The Katyusha rocket was less accurate, more fragile, and took longer to reload than the typical rocket launchers of WWII, but they were inexpensive, easy to produce, and it usually didn't matter if you missed when firing 18 rockets.