Development of the situation in Greece had frustrated Germans’ hopes for quick conquest of Greece by Italy. Quite the contrary, Berlin contemplated a possibility to face a broader anti-fascist coalition in the Balkans, including Turkey siding with the British. Also the Bulgarian government warned Berlin that Yugoslavia also might change its policy. In those circumstances Adolf Hitler decided about an intervention in Greece. However, such an intervention required additional political manoeuvres. It was necessary to attract Bulgaria and Yugoslavia to the «Axis», neutralize Turkey, obtain Romania’s consent to increase the contingent of the German troops in that country, and obtain Hungary’s consent for transporting the troops via its territory. It was also important to mask all those actions in a way that would not alarm the Soviet Union. Moreover, the military operation against Greece had to be completed soon enough to engage the participating troops against the USSR before May 1941. Hence the obvious tendency had emerged to solve the Italo-Greek conflict by «peaceful» means. Politicians in Berlin expected that merely a threat of a German intervention would be enough to force Greece’s capitulation.
On 3 November 1940 Berlin received a message – after all a false one – that apart from the Crete the British had installed themselves also on the Lemnos Island. In case if they had installed there an air base, their bombers would have been able to reach Romanian oil fields. Hitler immediately ordered to prepare an operation in north-eastern Greece and strengthen German fighter aviation in Romania.
Those orders had materialized in the Directive No. 18 from 12 November. In the part concerning the Balkans it instructed the command of the land forces to prepare an offensive operation codenamed Marita. Its objective was to seize the Greek territory north of the Aegean Sea through military operations driven from Bulgaria. Ten divisions were designated to achieve this task, as well as to keep Turkey at bay.
In the second part of November the projects of the concentration and operation plans were ready. On 5 December Field-Marshal Walther von Brauchitsch and Gen. Franz Halder had referred them before Hitler. Then Hitler demanded to extend the operation as far as to Athens. He had also emphasized the necessity to increase the German forces with another six divisions, should they happen to fight in the European part of Turkey. He left the final decision to commence the operation Marita to himself.
After the conference with Hitler the Supreme Command of the Armed Forces (OKW) within a week worked out the directives concerning execution of Marita. It had to be carried out by the 12th Army commanded by Field-Marshal Wilhelm List. It possessed almost 18 divisions, including 4 armoured divisions, one motorized division and one reinforced motorized SS regiment. Six divisions were designated for operations in Greece, and other divisions had to assume defences in case of a Turkish or Soviet counter-action. [Flood] The 12th Army had to be concentrated in Romania before 25 January
1941, so any time after that date it would be able to move in Bulgaria within 12 hours. The army would commence the operations in Greece latest on the thirty-fifth day after the entry to Bulgaria. The air forces had detached for the 12th Army eight reconnaissance squadrons and thirteen anti-aircraft artillery squadrons. To provide the air support for the 12th Army there was the VIII Air Corps of 281 combat aircraft detached from the Luftwaffe operation forces. [Flood]
The process of planning operation Marita was heavily influenced by the process of preparing the war on the Soviet Union. Marita had furnished an opportunity to mask the deployment of the German forces on the southern flank of the initial positions for the attack on the USSR. However, there was a chance that the hitlerite plans in that part of Europe would be exposed, and first of all that the invasion of the USSR, planned for 15 May 1941, would be delayed. So the Germans tried to achieve their goals in the Balkans without significant engagement of their forces, or at least having limited that engagement to the necessary minimum. To achieve that the German diplomacy was forced to make impressive stunts.
Hungary’s consent for transit of the troops to Romania was acquired relatively easily. Those were the talks with Bulgaria that brought most of the problems. The question of the possible reaction of the USSR, Turkey and domestic public opinion made Sofia delay under every possible pretext the final consent for entry of the German troops. Nevertheless, German reconnaissance units had been working in Bulgaria already since December 1940. Also the talks with Yugoslavia did not produce any seizable outcome, although there the Germans expected declaration of neutrality and lured Belgrade with a perspective to cease Salonika to Yugoslavia. Then, a lot of concerns were tied with the position of Ankara, and the German diplomacy strove really hard to keep Turkey neutral. And finally there was the question of the German relations with the Soviet Union, which since some time had been expressing its concern with the «Axis» steps in the Balkans. Hence Berlin concocted a scheme to convince Moscow that Germany conducted a «friendly» policy towards the USSR, and invited the Soviet people’s commissar for foreign affairs, Vyacheslav Molotov, to visit Berlin. During the visit, which took place in November 1940, German leaders proposed Molotov delimitation of «spheres of influence» after a collapse of the «bankrupt» British Empire. Yet Molotov rejected those proposals. Simultaneously Berlin actually undertook, via unofficial channels, an attempt of mediation between
Greece and Italy for a «peaceful» solution of the conflict. Yet that mediation would come with strings attached: Greece had to severe her relations with Great Britain. This way the guarantor of Greece’s security in dealing with Italy and Great Britain would be… Germany. Probably the best illustration of the German point of view on the Greek question is Hitler’s remarks during the aforementioned conference on 5 December:
The menace of the German retaliatory steps against Athens has brought this effect that so far no air raids have been made from Greece on the territories in which Germans have been directly interested; this state of matters probably will not change in the coming months. Nevertheless a German intervention in Greece is necessary to clear the situation in that area, unless Greece will put the end to the conflict with Italy and force the British to relinquish her territory. In that case no intervention will be necessary, since the question of the European hegemony will be solved not in Greece. In any case the concentration for the case Marita is unconditionally necessary and must commence in the beginning of March. In case it turns that it is redundant, the concentration will not be wasted, since the concentrated forces will be used in the Eastern campaign. [Halder]
At the end of December 1940 began transportation of the units of the 12th Army to Romania. At the end of February 1941 its first and second echelons were ready to march in to Bulgaria. That concentration of the troops caused that the Bulgarian czar Boris III, who under various pretexts, and not without influence of the Soviet and British diplomacy, evaded any direct involvement with the «Axis», now was forced to accept that solution. On 28 February the Germans started building bridges across the Danube, and on 1 March in Vienna the prime-minister Prof. Bogdan Filov signed the act of Bulgaria’s access to the «Axis». On 2 March the 12th Army crossed the Bulgarian border, and seven days later deployed on the Bulgaro-Greek frontier. By the second half of the month the whole first and second echelons of the 12th Army were moved to Bulgaria, and the third echelon left the Reich for Romania. Greece however did not succumb to the black mail. It decided to fight the German army, and allowed landing of the British Expeditionary Corps.
On 17 March 1941 Hitler decided to start the war on Greece before 1 April, and conduct it until Athens and the Peloponnese be taken. The units of the main forces of the 12th Army started accordingly deployment on the initial positions for advance.