Battlefront Ukraine, Summer 1942 : Soviets steadfast defenses and harsh winter conditions stalled German offensive against Moscow in Dec 1941, central Soviet Union. Resumption of battles in 1942, Germans shifted operational emphasis to southern front to secure Ukrainian wheat production and Caucasus oil fields. Soviets launched counter-offensive against German drive in Ukraine, targeting transportation hub Kharkov as pincer point. Soviet offensive fell into German encirclement, losing about 210,000 causalities, 650 tanks, 1700 guns, and 60,000 horses. Thus, paving the way for German advance into Don river basin and Caucasus regions. Second Battle of Kharkov - en.wikipedia.org/wiki/Second_Battle_of_Kharkov

German captured transportation hubs Rostov-Na-Donu and Nizhne-Chirskaya on Don river, then splits its offensive eastward against Stalingrad and southward into Caucasus region. Logistical problems emerged as vast Soviet landscape outstretched German supplies. For a period, 4th Panzer Army ran out fuel while 6th Army ran out of ammunition. Note in late-1950s, Soviets renamed Stalingrad to Volgograd to purge Stalinistic imagery from daily life. Volgograd - en.wikipedia.org/wiki/Volgograd

Rollover : Hitler set Stalingrad capture as priority by transferring 4th Panzer Army from Army Group A to augment Army Group B investing the city. 3rd Panzer Division remained with Army Group A and proceeded to conquer the Caucasus, almost reaching city of Grozny (in mid-1990s, it was the Chechen capitol which attempted to secede from Russian Federation resulting in decades long civil war). Grozny - en.wikipedia.org/wiki/Grozny

Propaganda Photo-Op was achieved when German Gebrigs (mountain) unit scaled Mount Elbruz to hoist the German national flag. In addition, Reichskommissariat Kaukasus (Reich's Commissariat Caucasus): German political occupation authority, was organized to rule the subjugated people and resources in Ukraine-Caucasus regions. Reichskommissariat Kaukasus - en.wikipedia.org/wiki/Reichskommissariat_Kaukasus

Unfortunate for the Germans, massive Soviet counter-offensive against Stalingrad salient on 19 Nov 1942 encircled over 220,000 of German 4th Panzer Army and 6th Army. Continuous attacks along Don River basin towards Rostov-Na-Donu threatened to completely cut off German Army Group A in Caucasus region. 3rd Panzer Division suffered heavy losses near Mozdok, hence entire Army Group hastily retreated through Rostov and setup defensive positions north bank of Don River by Dec 1942. Time it took for Army Group A to extricate itself from Caucasus, temporarily shifted resources from Stalingrad relief battles. By Jan 1943, German forces inside Stalingrad no longer had sufficient supplies to breakout of encirclement, over 90,000 Germans surrendered to Soviets in Feb 1943.