was defeated by an operation from Aden. For six months, Nouailhetas remained willing to grant concessions over the port and railway but would not tolerate Free French interference. In October the blockade was reviewed but the beginning of the war with Japan in December, led to all but two blockade ships being withdrawn. On 2 January 1942, the Vichy government offered the use of the port and railway, subject to the lifting of the blockade but the British refused and ended the blockade unilaterally in March. Northern front, 1941 Operation Camilla Operation Camilla was a deception concocted by Lieutenant-Colonel Dudley Clarke to deceive the Italians, making them believe that the British planned to re-conquer British Somaliland with the 4th and 5th Indian divisions, transferred from Egypt to Gedaref and Port Sudan. In December 1940, Clarke constructed a model operation for Italian military intelligence to discover and set up administration offices at Aden. Clarke arranged for the Italian defences around Berbera to be softened up by air and sea raids from Aden and distributed maps and pamphlets on the climate, geography and population of British Somaliland; "Sibs" (, hisses or whistles), were circulated among civilians in Egypt. Bogus information was planted on the Japanese consul at Port Said and indiscreet wireless messages were transmitted. The operation began on 19 December 1940 and was to mature early in January 1941. The deception was a success but the plot backfired when the Italians began to evacuate British Somaliland instead of sending reinforcements. Troops were sent north into Eritrea, where the real attack was coming, instead of to the east. Part of the deception, with misleading wireless transmissions, did convince the Italians that two Australian divisions were in Kenya, which led the Italians to reinforce the wrong area. Eritrea In November 1940, Gazelle Force operated from the Gash river delta against Italian advanced posts around Kassala on the Ethiopian plateau, where hill ranges from bound wide valleys and the rainfall makes the area malarial from July to October. On 11 December, Wavell ordered the 4th Indian Division to withdraw from Operation Compass in the Western Desert and move to Sudan. The transfer took until early January 1941 and Platt intended to begin the offensive on the northern front on 8 February, with a pincer attack on Kassala, by the 4th and 5th Indian divisions, less a brigade each. News of the Italian disaster in