During the Second World War only two noteworthy contacts were ever made between Churchill and Field Marshall Smuts. The first occasion involved Smuts sending a telegraph message to Churchill from South Africa following the Allied triumph over the Italians at Cyrenaica, which, by February 1943 was now in British hands, and on this "good news" Churchill had deemed to make a broadcast. However, Smuts warned against this, saying, "Every broadcast is a battle". Yet the day after Churchill had set in motion his plan to turn Cyrenaica into the "beginning of a free Italy", General Erwin Rommel had arrived in Tripoli with specific orders from Hitler to drive the British out of Cyrenaica. This was something which Smuts had long feared and these fears were communicated to Churchill. The second occasion of any meaningful communication between Smuts and Churchill occurred also in 1943 on September 4. On this occasion Churchill telegraphed Field Marhsall Smuts to say that "Russia will be the greatest land power in the world after this war will have rid her of the two military powers, Germany and Japan, who in our lifetime have inflicted upon her such heavy defeats..." As a historian of the causes of the Second World War, I am sorry to say that I personally find nothing in my research that would remotely support the BBC documentary programme to which you refer.