British personnel disembark in Athens as part of the first wave of British military aid for the Greeks. Britain encouraged the Greeks to oppose the Axis, even though there were insufficient numbers of British troops in the Middle East to make this a viable strategy.
Although the Greek Government was resolute in defending the country from Italy, it did not wish to provoke Hitler, in the full knowledge that German military involvement could destroy Greece. The British, however, wished to develop an anti-Axis alliance in the southern Balkans. Churchill - and his foreign minister Anthony Eden - had hoped to bring in Turkey, Greece and Yugoslavia on the Allied side. Turkey was determined to stay neutral, however, and Yugoslavia and Greece needed the reassurance of massive military support before committing themselves to overt opposition against Germany, a commitment that Britain was clearly unable to provide.
Greece accepted air support from Britain to attack the Italians, but initially refused offers of full military aid in case this was deemed sufficient provocation to force Germany to take military action against them. Although it was likely that Hitler would have invaded Greece anyway, to ensure the stability of his southern flank prior to the invasion of the Soviet Union, the very fact that the Greeks had allowed the presence of RAF bases in Greece was sufficient to worry the Germans towards intervention. When the Greek Government became aware of German troop movements towards the Bulgarian-Greek border, the fear of German invasion became a reality. As a consequence, Greece accepted the offer of British military assistance.
Why the British should have wanted to become embroiled in the Balkans – when resources in the Middle East were so stretched - remains a controversial point. Churchill favoured British involvement in Greece simply because it was a way of fighting back at the Germans. Churchill was man whose enthusiasms regularly exceeded sound strategic decision-making, and usually his military advisors reined-in his wilder schemes for intervention. But during the early months of 1941, General Archibald Wavell, commander- in-chief in the Middle East, and other senior military officers surprisingly went along with the idea of intervention laid down by Churchill and Eden.
Apart from the fact that despatching an expeditionary force to Greece would remove troops from the vital North African theatre of operations, the British did not have sufficient resources to make an intervention succeed. The long supply line across the Mediterranean from Egypt to Greece was exceedingly vulnerable to aerial attack, and the British in the Middle East lacked the necessary aircraft - both in terms of quantity and quality - to defend this link. By contrast, the Axis forces had more than sufficient aircraft to dominate the skies over the Balkans and the surrounding coastal waters. The British army and navy would pay heavily for this deficiency in air power.
Under the command of Lieutenant General Sir Henry Maitland Wilson, a British and Commonwealth force was despatched to Greece on 5 March 1941. Wavell had originally told the Greeks that he would send two Australian infantry divisions, a New Zealand division, a brigade of Polish infantry and an armoured brigade plus artillery and supporting units, totalling over 100,000 men. In the event, the expeditionary force was considerably reduced to 58,000 soldiers. The infantry was supplied by the 2nd New Zealand Division and the 6th Australian Division (totalling nearly 34,000 men). Also included was the 1st Armoured Brigade (around 100 tanks) and two regiments of artillery.
Before the British could assume their positions in northern Greece, however, the Italians launched their spring offensive. The slow but steady volume of reinforcements that had crossed the Adriatic from Italy enabled the Italians to assemble 28 divisions for the attack, which were organised into the Ninth and Eleventh Armies, under the overall command of General Ugo Cavallero (who had replaced Soddu at the end of December). Italian confidence was such that Mussolini himself crossed over to Albania to oversee the impending victory.