In short, yes, the Third Reich's trade with Turkey and the Iberian Peninsula increased significantly during the Second World War. Although imports to Germany initially plummeted at the outbreak of war, the Fall of France and the conquest of the Balkans gave the Third Reich a land route to Turkey and the Iberian Peninsula. By the same toke, trade with neutrals like Switzerland and Sweden increased significantly.

Although foodstuffs like coffee or olive oil formed a portion of exports to Germany, the Third Reich turned to these neutrals mostly to resolve their shortages in strategic raw materials that were not available in German-held territory. Turkey was one of the major sources of chromium for the Third Reich and both Spain and Portugal provided Germany with tungsten. Both of these minerals were vital elements for modern arms production. Sweden provided Germany with around 25 percent of its imports for iron ore and Switzerland, due to a complicated arrangement with the Allies, provided both sides (although Germany got the bulk of Swiss production) with precision instruments.

The Four Year Plan's drive for national autarky pioneered the many techniques that the Third Reich would employ during the war to acquire these materials. Instead of an open trading system, the Third Reich in the late 1930s pursued bilateral trade agreements with states like the Republic of China for strategic materials. Part of this bilateral trade was paid for with hard cash, but increasingly finished manufactured goods, especially armaments, were part of how Germany paid for this material. The advent of war increased the tendency of Germany to rely upon a mixture of arms and hard cash to pay for strategic raw materials. The gold reserves of occupied Europe and the Jewish community were levied to pay for these imports. Yet, the Third Reich's dwindling gold reserves meant that arms exports became a more important source of payment for this raw material. German arms exports to Spain climbed from .08 million RM in 1939 to 76 million RM in 1942 and 258 million RM in 1943. Although German armed forces were suffering from shortages in equipment, arms exports to neutrals and German allies continued to keep Germany's precarious trade balance from sliding over a cliff. The Germans tried to stretch out delivery contracts over a long time to mitigate the impact of these exports on the German war effort, but Hitler himself would authorize the continued export of war material as vital for German war effort.

These neutral countries realized that they possessed an advantage over Germany as the war situation deteriorated for the Axis. The German ambassador to Turkey would lament in a 1943 report to Berlin that "in almost six years of working with the Turks I have found that they are skillful enough to find a loophole in any treaty instrument." The Turks would use their trade deals with the Germans as leverage in negotiations with the Allies and in turn use the threat of cutting off chromium exports to gain advanced military equipment. Spain used the war to replenish its gold reserves, although Franco's exports of foodstuffs to Germany meant that the war was a time of extended hardship and rationing for the Spanish population despite neutrality. Finally, although these raw materials alleviated bottlenecks in German industry, they did not eliminate them. These flanking neutrals were never able to provide Germany with the quantities of raw materials that the German industrial machine needed. As such, German war production had to rely upon ersatz substitutes for the raw materials that these neutrals were either unable or unwilling to supply the Third Reich.

Sources

Bowen, Wayne H. Spain During World War II. Columbia: University of Missouri Press, 2006.

Deringil, Selim. Turkish Foreign Policy During the Second World War: An "Active" Neutrality. Cambridge: Cambridge University Press, 1989.

Militargeschichtliches Forschungsamt. Germany and the Second World War, Volume V/II: Organization and Mobilization of the German Sphere of Power. Clarendon: Oxford University Press, 2003.