As so often in war, actions in one theatre are rarely taken in isolation from others.   Crete was to be no exception.  On the 23rd of August, 1939, a non-aggression pact was signed between Germany and Russia.  Hitler could now move on Poland with his Eastern flank secure.  However, as in the First World War, so now in the Autumn of 1940 the Balkans would influence events.  Bulgaria made demands on Rumania, Hitler compelled the Rumanians to comply but in return he had to give the Rumanians a territorial guarantee.  This brought German military commitments into an area which the Russians considered to be their "sphere of influence".  The Russians began to interpret this move by Germany as a violation of the non-aggression pact.

At a conference in Bad Reichenhall on the 29th July, 1940, Colonel General Jodl, Chief of Staff of the German Forces told a small planning group of Hitler's intention to "take action against this menace of the Soviet Union".  This was the beginning of the planning of Barbarossa, the German invasion of Russia.  The start of Barbarosa, and the timing of the invasion of Crete were to be closely linked.  Hitler had also allied Germany with Italy, and her histrionic leader, Mussolini, El Duce as he liked to be called.  Mussolini was keen that Italy should be seen in the alliance to also cover herself with military glory.  He was keen for a military victory somewhere, and soon.  Hitler however did not want Italy upsetting the delicate balance in the Balkans.  Unfortunately Hitler decided that the situation in Rumania required that he should move his troops into that country, but he would not inform Mussolini, a decision that caused great resentment when Mussolini heard of it.  At this same time Hitler had received a setback to his plans on his Western Front.  The Luftwaffe had failed to defeat the Royal Air Force in the Battle of Britain, and consequently he had also had to postpone indefinitely his plans for an invasion of Britain.

Mussolini, put out by Hitler's move into Rumania, decided in October 1940 to invade Greece.  On October 28th the Italian Minister in Athens presented an ultimatum to General Metaxas.  At the same time the Italian army in Albania invaded Greece.   The result of this was that Greece invoked the guarantee given to them by Chamberlain in April 1939.  The 2nd Battalion of the York & Lancaster Regiment as well as the Black Watch were put on 6 hours notice to move, as of 6pm on the 29th October.  The invasion did not go well for Italy.  Mussolini's plans were ill thought out, and there were not adequate forces deployed for the invasion.   The result was a humiliation for Mussolini, with significant follow on effects.   The invading Italian army was forced to retreat and a Fleet Air Arm attack on the Italian Naval Base at Taranto resulted in the loss of three Battleships and two heavy Cruisers.  In North Africa where, in September Italian forces had invaded Egypt from Libya, there was a further reversal of fortunes. In December the British Army attacked the Italians at Sidi Barani and drove the Italians back.

Prior to the British defeat of the Italians in N Africa, there were very real differences of opinion between Churchill and his Mediterranean commanders over strategy.   Churchill was keen to move forces to Greece and Crete to defend the Eastern end of the Mediterranean.  At the same time he was convinced that General Wavell, Commander-in-Chief, Middle East, was planning only for defence. Wavell was in fact planning a daring attack against the Italians, but would not communicate this to Churchill by signal, only by word of mouth.  Anthony Eden ( Minister of War ) was in Egypt at this time and received a number of telegrams from Churchill putting forward his views on the need to assist Greece, and strengthen Crete, "no one will thank us for sitting tight in Egypt with ever-growing forces while Greek situation and all that hangs on it is cast away".  He said he was "trying to send substantial bomber and fighter reinforcements to Crete and Greece...".  The British commanders in the Middle East held the strong view that the defence of Egypt was absolutely paramount, forces should not be diverted to Greece when they were needed for an offensive in the desert, and that included Air Force units.   This view was supported by an appreciation written by the Joint Planning Staff on the 4th November.  An offensive of which Churchill was unaware.  Admiral Cunningham, who commanded the Navy in the theatre, believed that a large military garrison on Crete was not necessary.  One Battalion and A.A. defences would be adequate.  It was felt that the minimum defence should be 24 HAA (Heavy A.A.) guns and 24 LAA (Light A.A.) guns, with two 6-inch coast defence batteries.  The actual position at that time at Suda Bay was 8 HAA and 12 LAA guns with some naval guns for coast defence, and the two 15-inch guns of HMS Terror.  Because of the presence of the latter, it was felt not necessary to send the 6-inch batteries.

On November 8, 1940, Eden arrived back in London to brief Churchill and his military staff on the offensive plans of Wavell, the plans that had been too secret to send by signal.  The Italians were to be attacked and destroyed in the desert.   Churchill was delighted "Here was something worth doing."  The operation was code named COMPASS.

Towards the close of 1940 Hitler's thinking was more and more pre-occupied with his growing intent to invade Russia.  With the collapse of the Italians in Greece and North Africa, both Crete and Greece took on a new priority for Hitler.  Operation MARITA was the plan for the occupation of all of Greece if needed, as well as an airborne invasion of some of the Greek islands.  He intended a short, one month, campaign, starting in March.  On successful completion, the troops would be re-assigned to Russia.  The priorities of Barbarossa would determine the timing of events in Crete.

Strategically placed across the sea routes between Britain's North African bases, and the destination of the Commonwealth troops in Greece, lay the island of Crete.  The island had a magnificent natural harbour at Suda Bay, and two much smaller harbours at Heraklion and Rethymnon.  However, these were the only harbours capable of accepting vessels larger than fishing boats and as they lay on the north coast it meant that the Navy would be vulnerable to air attack from Greece while supplying these ports.  There were also three airfields, one at Maleme to the west of Hania, another at Rethymnon and the third at Heraklion.  There were no railways on the island (that remains true today), and only one decent road along the northern coast.  Behind the coastal road is a range of mountains rising to some 9000 ft, a very rugged area, as the troops were later to discover.  Only one road crossed the mountains from north to south, finishing on the steep cliffs above the fishing village of Sfakia.  

The geography of the island meant that defence would take place in pockets, with mutual reinforcement difficult.  Also, while the need to defend the island had been accepted there would be other priorities, Greece and North Africa, that would also be contesting for the scarce resources available to the C-in-C Middle East, General Wavell.

Sadly, this critical strategic island was not adequately strengthened while the Commonwealth forces moved into Greece.  This neglect would have serious consequences when the German forces invaded. Churchill, in his "The Second World War", later wrote that "it remains astonishing to me that we should have failed to make Suda Bay the amphibious citadel of which all Crete was the fortress".