'Cordite Cover Plan' was a British unrealised deception plan created to facilitate the proposed 'Cordite' amphibious assault on and seizure of the island of Rhodes in the Italian-held Dodecanese islands group (March/April 1941).
By a time late in March, the forces of General Sir Archibald Wavell, the British commander-in-chief, Middle East, had expelled the Italians from the Cyrenaican eastern part of their colony of Libya, and patrols ahead of the main British forces had pushed as far to the west as El Agheila in the south-eastern corner of the Gulf of Sirte. At much the same time, on the European continent German forces had entered Bulgaria and now threatened Greece, which was already at war with Italy. In 'Lustre', Wavell sent forces to the aid of the Greeks, and earmarked one division for the 'Cordite' operation to seize Rhodes and the rest of the Italian-held Dodecanese islands, off the coast of Turkey.
To support this, Lieutenant Colonel Dudley W. Clarke, heading the Middle East Command’s fledgling deception apparatus, created the 'Cordite Cover Plan'. The objective of the plan was to persuade the Italians to divert forces from well-garrisoned Rhodes to the altogether more weakly held island of Kárpathos, which was known to the Italians as Scarpanto, about mid-way between Rhodes and Crete, and on Rhodes itself to redeploy the bulk of their surviving forces the northern side of the island, where 'Cordite' was to take place, to the southern side.
The 'story' to be promulgated to the Italians was that it was Kárpathos rather than Rhodes which was the real objective (by a nice twist this had actually been considered at one time), and that a simultaneous diversionary raid was to be made on an airfield at the southern end of Rhodes by the fictitious 1st SAS Brigade, which was to be transported from its supposed current base in Transjordan to Crete for that purpose. According to the deception plan, the British attack was to be made once week later than the date actually set for 'Cordite'.
As it was appreciated that Axis intelligence would quickly discover that the division earmarked for 'Cordite' departed Egypt, the delay was to be ascribed in the 'story' to the British intention to pause at Cyprus in order to undertake a full rehearsal of the operation.
The 'Cordite Cover Plan' was not put into effect as 'Cordite' was cancelled when, at the end of March, German troops who had started to reach North Africa under the command of Generalleutnant Erwin Rommel early in February in 'Sonnenblume' rapidly, drove Lieutenant General Sir Richard O’Connor’s Western Desert Force back into Egypt.
Even so, the creation of the 'Cordite Cover Plan' had been an invaluable exercise inasmuch as it brought together, for the first time, four elements of the successful deception plans of the future. Firstly, it revealed the importance of starting a deception with a full 'story' as the scenario on which all deception activities could then be constructed on a consistent basis. Secondly, it confirmed the value of creating the 'story' on the basis of an alternative operational plan which had been considered and discarded. Thirdly, it introduced the factor of neat timing by persuading the opposition that the proposed operation was scheduled for implementation than the real operation. Fourthly, it pioneered the notion of persuading the opposition that the real operation was only a feint.