Nine times out of ten an army has been destroyed because its supply lines have been severed.
General of the Army Douglas MacArthur

SUPPLIES WERE obtained either through successful logistics or by capture.

"The siege of Tobruk was not, like some famous sieges, a struggle for survival in the face of dire shortages of food or water or munitions. Shortages there were at times but never so acute that men were starving or guns without rounds to fire" [1]

The Axis tried to cut supply to the Tobruk garrison. The Allies tried to cut supply to Tripoli. Success or failure to attack supply lines depended on many occasions on other commitments.

For example, the ferrying of British forces from Egypt to the Port of Piraeus (Athens) to support Greece required considerable commitment from the British fleet. Consequently, Axis supplies were able to reach Tripoli from Italy.

To interrupt Allied supply, the Luftwaffe dropped magnetic mines in the Suez Canal.

Despite the Axis blockade, supplies still managed to get through to Tobruk by sea. This was at considerable cost to the allied navies which ran the gauntlet of Axis submarines and aircraft. Twenty-five warships and five merchant ships were lost on the 'Tobruk run'. The Western Desert Lighter Flotilla ("We die like flies") was Tobruk's lifeline during the siege.

The British navy was instructed to block the Axis supply line by sinking the aging British battleship Barham in the port of Tripoli. Admiral Cunningham rejected this idea and instead conducted an ineffectual raid on Tripoli with surface ships and aircraft.

One of the most effective weapons against the Axis supply line was the submarine. In The Fighting Tenth, John Wingate recounts a report on 9 September 1941 to Berlin by Vice-Admiral Weichold, the head of the German naval staff in Rome, on the impact of British submarines in the Mediterranean.

Now, as formerly, the most dangerous British weapon in the Mediterranean is the submarine, especially, those operating from Malta.

In the period covered [11 July - 31 August 1941] there were 36 submarine attacks in the Mediterranean, of which 19 were successful. In spite of improved harbour defences, submarines lurking in or just outside the harbours have sunk or damaged eight ships.

A very severe supply crisis must occur relatively soon. This is because Italian freight space which is sunk cannot be adequately replaced, and also because air transport can never be a complete substitute for sea transport.

On May 1 Churchill's Tiger Cubs arrived in Alexandria. A total of 238 tanks.

Japan entered the war on 7 December 1941. Suddenly British interests were threatened in Asia. Allied supplies and troops bound for North Africa were diverted to face the Japanese.