By August of 1942 reinforcements sent to assist Army Group B's drive on Stalingrad had transformed the German Sixth Army from a potent assembly of men and machines to the most powerful army in the world, with 22 divisions and supporting units under the command of General Friedrich Paulus. Facing the Sixth Army, and Fourth Panzer Army's seven German and four Romanian divisions, was a Soviet Stalingrad Front that had been decimated in July.
The German assault on Poland began at 4:45 am on September 1, 1939. The Polish air force, dispersed prior to the invasion, instead of rising en masse to challenge the Luftwaffe, saw its numbers quickly whittled down in a misguided hope to preserve its striking power. The Polish army fought mostly alone, while German planes pounded the Polish capital. Within just two weeks, German artillery and airpower had killed over 60,000 of Warsaw's citizens.
Japan and the Soviet Union clashed repeatedly late in the 1930s most notably in 1938 near the Soviet port of Vladivostok, and then again in a massive battle in 1939 on the Soviet controlled Mongolian border at Khalkin Gol - Nomonhan. At Khalkin Gol the Red Army decisively defeated Japan, ultimately causing the Japanese to abandon plans for invading Siberia with up to 45 infantry divisions.
In May of 1942 the British Eighth Army comprised 100,000 Commonwealth soldiers, well equipped, and deployed in depth west of Tobruk along a thirty-five mile frontage. U.S. Lend-Lease aid to Britain had played a prominent role in well equipping Eighth Army. For instance, the British 1st and 7th Armored Divisions included 316 American built tanks. Although 149 were the light Stuart tanks, Eighth Army also fielded more powerful tanks than did Germany, such as 167 of the American M3 "Grant" tanks. The "Grant" featured a hull mounted 75mm gun, and turret mounted 37 mm high velocity gun.
In the spring of 1942 Soviet General S. K. Timoshenko led one of the Red Army's several attempts to wrest the initiative from the Germans in this case by launching an offensive from the Izyum salient and designed to destroy Germany's Army Group South and push on to Kiev. The Izyum salient was located in a stretch of flat tank friendly land situated within a larger region featuring great bends in the Dnieper, Don, and Donets Rivers, it was so named because of the city of Izyum's location at the salient's base.
On March 4th Marshal of the Soviet Union Georgy Zhukov's 1st Ukrainian Front, including the 3rd Guards Tank Army and 4th Tank Army, attacked German Army Group South's left wing and forged numerous penetrations in German defensive lines already heavily weakened following the battle for the Korsun pocket.
The failed Axis offensive at Kasserine Pass meant that by March of 1943 the Axis were doomed in North Africa. The Axis were trapped between two powerful armies and reliant on a logistical chain perpetually in crisis, as the Allies enjoyed overwhelming naval superiority and new air bases in Algeria and Libya to launch attacks on Axis shipping. The Axis had maneuvered a quarter of a million soldiers and huge stores of equipment and supplies into a dead end. General von Arnim, commanding Army Group Afrika, actually surmised the odious Axis supply situation meant U.S.
In December of 1939 the German surface raider and "pocket" battleship Admiral Graf Spee had finally been brought to battle by three cruisers from the British Royal Navy. Operating primarily in the South Atlantic during the fall of 1939 the Graf Spee sank numerous British merchantmen. However, the Royal Navy, after mobilizing significant assets to stop the Graf Spee, finally caught up with the German warship and after a running battle in which the Graf Spee sustained serious damage the Graf pocket battleship's captain decided to scuttle his vessel rather than attempt to fight his way past the
Following Hitler's December 1941 declaration of war upon the United States German Admiral Karl Doenitz sought to take advantage of the weakly guarded sea-lanes near the American coast and pick off the highly vulnerable, solitary, merchant ships plying these waters. Hitler approved Doenitz's plan, code named Operation Paukenschlag, or drumbeat/roll the drums. Doenitz' U-boats would carry Hitler's war to America and if successful deliver the first blows designed to cripple American shipping and industry.
In mid-November 1941 Field Marshal Fedor von Bock's Army Group Center began the final phase of the German assault on Moscow spearheaded by the Third Panzer Army and Fourth Panzer Army. Some 233,000 men, 1,300 tanks, 1,880 guns and 800 aircraft efficiently split Rokossovsky's 16th Army and Leliushenko's 30th Army as the Germans hammered away at a similar number of Russian men and aircraft but far less guns and tanks; the Russian defenders could only put 1,254 guns and 502 tanks into the field.