The Secret History of MI6 - Keith Jeffery [339]
Green’s agent Sectude continued transmitting until January 1942 when Japanese surveillance obliged him to sign off, but he did so with a cheery message: ‘Of course nothing changed between us. Listen in. Goodbye. Good luck.’ The agent had told Green to monitor the English-language broadcasts of Radio Saigon for particular phrases. ‘You are listening to Saigon’, for example, was to mean ‘shipping concentration in Saigon river’, and ‘Good night to you all’ at the end of a broadcast meant ‘reinforcements sent to Malaya’. In February Calcutta reported that ‘information from 65100 [Sectude] by Saigon broadcasts’ was ‘being received in Burma’. Some direct contact was maintained with Sectude, who requested a replacement wireless set in August 1942 ‘to operate from Hanoi’. In January 1943 one of Green’s agents swam across the Red River at Hoikow (Haiku), where the railway crossed the border between China and French Indo-China, only to be told that Japanese surveillance made wireless operation difficult and so intelligence collected by Sectude was brought out by courier across the Chinese border to Kunming.
Advance warning of the Japanese attack was also passed to the Americans through Gerald Wilkinson in Manila. Two telegrams sent by Wilkinson to the SIS sub-station in Honolulu have survived in the archives (though only as paraphrases). On 26 November, citing ‘Secret source (usually reliable) ’, he reported that the Japanese would attack the Kra isthmus (in southern Thailand) from the sea on 1 December ‘without any ultimatum or declaration of break with a view to getting between Bangkok and Singapore. Attacking forces will proceed direct from Hainan and Formosa. Main landing point is to be in Songkhla area . . . American military and Naval Intelligence Manila informed.’ The second signal was sent on 2 December and comprised the text of a wire which Menzies had sent to Wilkinson. ‘Most immediate,’ it read. ‘We have received considerable intelligence confirming . . . accelerated Japanese preparation of airfields and railways [and] arrival since November 10th of additional one hundred thousand troops . . . and considerable quantities fighters, medium bombers tanks and guns (75 mm).’ The conclusion at Head Office was ‘that Japan envisages early hostilities with Britain and United States. Japan does not ?intend attack Russia at present but will act in South. You may inform chiefs of American Military and Naval Intelligence Honolulu.’2 These reports were only two of many indicating heightened Japanese activity, and whether or not the intelligence made any practical difference to the defence of Malaya, the 26 November prediction was remarkably accurate. The main Japanese landing on 8 December was indeed at Songkhla in southern Thailand. SIS, however, does not appear to have had any knowledge of the perhaps tactically more important landing further south at Kota Bharu, just inside Malaya.3
Gerald Wilkinson went on to play an important role as the main British liaison with the American General Douglas MacArthur, reporting through Menzies eventually to Churchill himself. In the dark days before the fall of the Philippines Wilkinson used his SIS secure radio link to transmit