Britain was bound to assist Greece by the declaration of 1939, which stated that in the event of a threat to Greek or Romanian independence, "His Majesty's Government would feel themselves bound at once to lend the Greek or Romanian Government [...] all the support in their power." The first British effort was the deployment of RAF squadrons commanded by John d'Albiac, which were sent in November 1940. With the consent of the Greek government, British forces were dispatched to Crete on October 31 to guard Suda Bay, enabling the Greek government to redeploy the 5th Cretan Division to the mainland.
On November 17, 1940, Metaxas proposed to the British government the undertaking of a joint offensive in the Balkans with the Greek strongholds in South Albania as the base of the operations. The British side however was reluctant to discuss Metaxas' proposal, because the deployment of the troops the implementation of the Greek plan demanded would seriously endanger the Commonwealth military operations in North Africa. During a meeting of British and Greek military and political leaders in Athens on January 13, 1941 General Alexandros Papagos, Commander-in-Chief of the Hellenic Army, asked Britain for nine fully-equipped divisions and corresponding air support. The British responded that, because of their commitment to the fight in North Africa, and all they could offer was the immediate dispatch of a small token force of less than divisional strength. This offer was rejected by the Greeks who feared that the arrival of such a contingent would precipitate a German attack without giving them any sizable assistance.e[›] British help would be requested if and when German troops crossed the Danube from Romania into Bulgaria.
"We did not then know that he [Hitler] was already deeply set upon his gigantic invasion of Russia. If we had we should have felt more confidence in the success of our policy. We should have seen that he risked falling between two stools, and might easily impair his supreme undertaking for the sake of a Balkan preliminary. This is what actually happened, but we could not know that at the time. Some may think we builded rightly; at least we builded better than we knew at the time. It was our aim to animate and combine Yugoslavia, Greece, and Turkey. Our duty so far as possible was to aid the Greeks."
Churchill held to his ambition to recreate a Balkan Front comprising Yugolavia, Greece and Turkey, and ordered Anthony Eden and Sir John Dill to resume negotiations with the Greek government. A meeting attended by Eden and the Greek leadership, including King George II, Prime Minister Alexandros Koryzis—the successor of Metaxas, who had died on January 29, 1941—and Papagos took place in Athens on February 22. There the decision to send a British Commonwealth expeditionary force was made. German troops had been massing in Romania and on March 1, 1941, Wehrmacht forces began to move into Bulgaria. At the same time, the Bulgarian Army mobilized and took up positions along the Greek frontier. On March 2 Operation Lustre, the transportation of troops and equipment to Greece, began and 26 troopships arrived at the port of Piraeus. On April 3, during a meeting of British, Yugoslav, and Greek military representatives, the Yugoslavs promised to block the Strimon valley in case of a German attack across their territory. During this meeting, Papagos laid stress on the importance of a joint Greco-Yugoslavian offensive against the Italians, as soon as the Germans launched their offensive against the two countries.f[›] Until April 24, more than 62,000 Commonwealth troops (British, Australians, New Zealanders, Palestinians and Cypriots) were sent to Greece, comprising the 6th Australian Division, the New Zealand 2nd Division, and the British 1st Armoured Brigade. The three formations later became known as 'W' Force, after their commander, Lieutenant-General Sir Henry Maitland Wilson.g[›]