Birger Dahlerus Johan Birger Essen Dahlerus ( February 6 , 1891 – March 8 , 1957 ) was a Swedish businessman , amateur diplomat , and friend of Hermann Göring who tried through diplomatic channels to prevent the Second World War . His futile diplomatic efforts during the days preceding the German invasion of Poland in 1939 are sometimes called the Dahlerus Mission . Biography . Birger Dahlerus was born in Stockholm in 1891 . He had an excellent network of contacts of authoritative Englishmen and various leaders of the Third Reich , - - - - " e . g . " his early acquaintance with Hermann Göring . It had been known to the senior military personnel of the Third Reich , at least since the Military Conference of August 6 , 1939 at Obersalzberg , that aggressive war between Greater Germany and the Western powers was imminent . On August 7 , 1939 Dahlerus arranged a meeting at his own house , near the Danish border in Schleswig - Holstein , between Göring and seven British businessmen . The businessmen attempted to persuade Göring that the British Government would stand by its treaty obligations to Poland , which obliged it to support the Polish Government in any conflict in which it became embroiled . Dahlerus believed that they had succeeded . At the Nuremberg trials , the British prosecutor , Sir David Maxwell - Fyfe , was able to persuade the Swede that he had been badly misled by the German leaders . Clearly , the discussion had no effect on the policy and actions of the Third Reich . On August 25 , 1939 , the British and Polish Governments converted the unilateral declaration of support offered by the British Government into a mutual assistance pact . On the same day Benito Mussolini wrote to Hitler to indicate that he would not be able at this time to declare war on the Western Powers . Dahlerus , at this time , was acting as an intermediary between Göring and the British Foreign Secretary , Lord Halifax . Göring had summoned Dahlerus from Stockholm on the previous day , put him on an aircraft , and dispatched him to inform the British Government that Germany wanted an understanding with Great Britain . Halifax informed him that diplomatic channels were open and that his input was unnecessary . Following a telephone conversation between himself and Göring , Dahlerus had a further conversation with Halifax on August 26 . He persuaded the British Foreign Secretary to write a letter , couched in non - specific terms , indicating the desire of the British Government for peace and requesting a few days leeway in which to achieve it . On August 27 Dahlerus flew to London , and met Neville Chamberlain , Lord Halifax , Sir Horace Wilson and Sir Alexander Cadogan . He presented an offer , which included a proposal that Britain would agree to Germany offering to guarantee the borders of Poland , taking Danzig , and a referendum in the Polish corridor . This very modest proposal was nevertheless felt to be unacceptable , and that the Poles would fight rather than agree to it . It was agreed that Dahlerus would return to Berlin and report back with Hitler ' s reply . Dahlerus had become so significant , according to his own testimony , that he felt able to advise the British Government that they should keep Ambassador Neville Henderson in London until the next day so that he could better react to Hitler ' s response . On August 29 , at a meeting with the German Foreign Minister , Joachim von Ribbentrop , Neville Henderson had been presented with a document containing sixteen points which Germany demanded that Poland agree to . Henderson said that they were spoken too fast for him to understand , and that he was denied a written copy . On the following day , Dahlerus was given a copy of the sixteen points by Göring , and took them to Henderson . Henderson in turn dispatched him to Józef Lipski , the Polish ambassador , who had never heard of Dahlerus . As one of the sixteen points was that a Polish negotiator with full plenipotentiary powers should appear in Berlin before September 1 , the Polish Government deemed the proposals unreasonable . On August 31 Lipski was received by Ribbentrop . On being asked if he had come as a fully empowered delegate , and on stating that he had not , he was dismissed . An intercepted copy of the telegram to Lipski , defining his powers , was given by Göring to Dahlerus to take to Henderson . Dahlerus ' final diplomatic effort before the onset of war occurred on the afternoon of the last day of peace . He proposed that Göring should again meet with Henderson , which he did at 5pm . Sir George Ogilvie - Forbes , counsellor and chargé d ' affaires at the British embassy , was also present . His statement , presented at Nuremberg , describes the atmosphere as negative , and suggests Göring ' s confidence in the ability of Germany to crush Poland quickly . The Third Reich commenced land operations against Poland on September 1 , 1939 at 04 : 45 . At 08 : 00 Dahlerus met Göring , who informed him that the Poles had attacked Germany ( sic ) at Dirschau . Dahlerus , in his Nuremberg testimony , says that " I informed somebody that according to the information I had received the Poles had attacked , and they naturally wondered what was happening to me when I gave that information " . Dahlerus also stated that " the Poles are sabotaging everything " and that he had " evidence they never meant to attempt to negotiate " . Dahlerus telephoned London again at 12 : 30 , and this time was put through to Cadogan . Cadogan , while being a committed anti - appeaser , was only the Under - Secretary of State , and Dahlerus insisted that his comments be submitted to the . They duly were , and the answer given to the Swede was that negotiation was only possible on the basis of the immediate withdrawal of German forces from Polish territory . The British and French Governments issued ultimata to the German Government on September 3 , 1939 . Dahlerus telephoned the British Foreign Office ten minutes before the British ultimatum expired , with a proposal that Göring should fly immediately to London for negotiations . Perhaps not surprisingly , the approach was rejected , and Dahlerus disappeared from the world stage until the Nuremberg trials , apart from a brief and ineffective liaison between Hitler and Forbes on September 26 , which achieved nothing . Birger Dahlerus died in Stockholm in 1957 .