Great question @hobbyhub – the answer is: partially, and indirectly.

By the end of 1940, the Germans knew they were going into the Soviet Union the next year. So von Ribbontrop and the Foreign Ministry starts working through the winter of 40-41 to build up a series of alliances in the southeast of Europe – Rumania, Bulgaria, Hungary, and Croat-dominated Yugoslavia, in order to brace the southern flank of this massive invasion. There were also overture made to Finland to bolster the northern wing, but that’s another story.

Everything’s great as the date for the invasion (first “Otto,” then “Barbarossa”) approaches – May 15, 1941. But two things happen to really screw things up for the Germans.

One – the Italians, who have previously conquered Albania, use Albania as a base for an invasion of Greece. They do very, very badly. In fact, Greece has soon counter-invaded back into Albania and taken a quarter of the country. Worse, the Italian invasion allows the British to make overtures to the Greeks as an “allied state” and before you know it, 35000 British troops are allowed to deploy in Greece. Now Germany has a British army on the flank of the upcoming Barbarossa invasion, AND within striking distance of the Ploesti oil fields in Rumania.

Two – the British manage to instigate a coup in Croat-dominated Yugoslavia. The Croat government was pro-German, they are bloodily overthrown by anti-German Serbs. The Serbs aren’t exactly pro-British, but they’re definitely pro-Russian and with Barbarossa coming up, there’s another major geopolitical problem on Barbarossa’s south flank.

So Germany postpones Barbarossa a little, pivoting south to launch a hasty invasion of Yugoslavia (April 6 1941 – “Operation Punishment”). The invasion continued down into Greece and eventually into Crete in May.

As a result of these two primary triggers, Barbarossa would be postponed from May 15 to June 22, with fateful consequences later down the road. 😀

The importance of Stalingrad … well, that’s a complex issue. We cover it in some detail here:

http://www.beastsofwar.com/groups/historical-games/forum/topic/wargaming-surviving-stalingrad-75th-anniversary/

It wasn’t just because of the name, operationally the Germans couldn’t bypass it because they needed this anchor “landing point” after crossing the Don Bend, the obstacle presented by the Volga River, the lack of an operational landing point east of the Volga, etc. And 6th Army was terribly unmobile, but that was after several of its panzer divisions were stripped off to Army Group A and 4th Panzer Army to support diverging attacks further south.

So Case Blue (specifically Stalingrad’s portion) was definitely a flawed offensive, and Stalingrad represents an objective pursued far too long after its cost had exceeded its prospective worth. 😀