ORIGINAL: Footslogger
Did the Caucasus have a rich food source? A completely unrelated quesion is this: If Hitler had taken the British out, would there have been more divisions available for Barbarosa in 1941?
The Caucasus was a veritable cornucopia of resources, especially if combined with the Donbas region. Food, mineral and fossil fuels abounded. But as several other threads pointed out, transporting that mineral wealth to the Reich would have been a headache.
Another important factor regarding the Caucasus was its geo-strategic position and the fact that its domination would have choked off one of the best roads for the lend lease supplies whcih went through Iran. It would also have brought Turkey firmly in the Axis camp or in the least would have made them even more subservient to German wishes (keep in mind that they also imported a lot of manganese from Turkey, more or less due to the latter's fear of provoking Hitler).
Also the Caucasus was inhabited by a group of people who were determined opponents of Communism. In fact, even the Germans who normally were quite ruthless in dealling with subject people, were for some reason, well disposed towards the numerous people of the Caucasus (see for example the career of von Pannawitz).
In a sense, the conquest of the Caucasus would have given them a secure 'shoulder' in the south to prosecute the war in Russia. And more in the realm of fantasy, there existed the remote possiblity of bringing the British to the negotiations table through threatening Iran (and its oil reserves) and India (the crown jewel). Although this is pure speculation, given the support that the Germans enjoyed amongst Muslims, the conquest of the Caucasus would have created further problems for the colonial empires.
Regarding the what if scenario of Hitler taking out the British first, it should be noted that till '43, the policy of the Wehrmacht was to send units which were badly shot up or under (re-)construction to France to recover their strength. In effect the original Barbarossa did include the bulk of the frontline forces of Germany with occupied France (not Vichy) being garrisoned by new formations, security divisions or garrison divisions of doubtful value (you know, the ones with 700+ numbering). A few mobile formations were also present as well. The same was the case of the Balkans (which was mainly the responsibility of the Italians, Bulgarians and other local powers like the Croations) with only a few frontline formations really available to fight Tito's partisans, let alone to move to the Russian Front. Other detachments were teh Africa Korps and a few other forces present in Italy. So in terms of number of divisions, the Germans wouldnt have gained much in front line strength unless they committed second line formations to the front.
however, the best effect such a one front war would have had would have been the concentration of the luftwaffe in one theatre. With the equivalent of 3 airfleets deployed in the west and the Mediterranean, in practice it had to deploy half of its strength away from the most crucial land front. A concentrated Luftwaffe would have immesurably aided the German war effort in the East.