The Perilous Mission of a Paris Banker during the ‘Phoney War’

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BNP Paribas Historical Collections

BNP Paribas Historical Collections

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by Hélène Bhys, Historia

How Jacques Allier, a senior banker at Paribas, managed to get hold of Norway’s stock of heavy water, thus thwarting Nazi Germany’s plans to develop an atomic bomb.

“16 March 1940. Received from Monsieur Allier 10 numbered drums […] containing deuterium protoxyde (heavy water). Signed Joliot-Curie.” Behind this laconic note lies an extraordinary adventure, which had begun a few weeks earlier. On 20 February 1940, Raoul Dautry, French Minister for Armaments, had introduced Jacques Allier, an authorised signatory at Paribas who had been called up for military service in late 1939 and seconded to the Minister’s technical staff, to the physicist Frédéric Joliot-Curie.  By the time the meeting ended, Allier had been tasked with a crucial mission: to obtain for France the stocks of heavy water needed to conduct experiments into nuclear fission.

The race for the bomb

Ever since the nuclear fission properties of uranium had been discovered in 1938, France, Britain and Germany had been engaged in a race against time to master the nuclear reaction process with a view to using as a weapon the massive release of energy which nuclear fission was expected to generate. By May 1939, a French team consisting of Joliot-Curie, Hans Von Halban and Lew Kowarski had achieved promising results, but had come up against the difficulty of obtaining sufficient quantities of the deuterium oxide, aka ‘heavy water’, needed to create an explosive nuclear chain reaction. At that time the only European firm in possession of a sufficient quantity was the Norsk hydro-elektrisk Kvælstofaktieselskab (Norwegian Hydro-Electric Nitrogen Company, generally known as Norsk Hydro). The need to purchase Norsk Hydro’s heavy water was all the more urgent as the Germans, whose research was at an extremely advanced stage, were also customers of the Norwegian producer. However, France had a definite advantage here: when Norsk Hydro was established in 1905, the company had primarily sought French capital as Paris was, in the early 20th century, a leading financial marketplace.  French investors, grouped under the umbrella of Paribas, had subscribed 90% of the founding capital and the bank had maintained close links with the company ever since. In 1940, Raoul Dautry was counting on these traditional commercial links to smooth the transaction, hence his appeal to Jacques Allier, who was one of the persons in charge of international relations at Paribas.

The Oslo mission

The purchase was becoming critically urgent. Norsk Hydro had just confidentially informed Paribas that the German customers had requested a substantial increase in their deliveries of heavy water. The Norwegian firm had declined the extra order on various pretexts but this development was clear evidence that the Germans were ready to go.  Armed with two sets of orders, Allier set off for Norway, travelling under his mother’s maiden name. This was a useful precaution because the Germans, who had meanwhile got wind of the affair, were already on the lookout for him. He landed at Oslo and immediately met with Norsk Hydro’s General Manager, Axel Aubert. Allier laid all his cards on the table, explaining to Aubert, whom he knew to be favourable to French interests, just what was at stake. The Norsk Hydro boss had no hesitation, not only in accepting Allier’s proposal but also offering to supply him with the company’s entire existing stock of heavy water without the need for immediate payment. He further agreed to arrange clandestine shipment of the chemical out of the country, thus avoiding any diplomatic complications, given that Norway maintained the status of a neutral country. Aubert’s action was all the more courageous in that he knew full well what a risk he was taking. In a moving message addressed to the French government, he pointed out: “If the experiment of which you have informed me succeeds and if subsequently France should be unfortunate enough to lose the war, I would be shot for what I have done today. Nevertheless I am proud to take this risk.” The only thing he asked for in return was that Allier take steps to put an end to rumours alleging that his company was sympathetic to Nazi Germany. Allier agreed unreservedly to this very reasonable request.

Discreet drums

A few days later, 185 kg of heavy water left the factory at Rjukan, in southern Norway, by night.  The factory manager drove the precious containers himself along icy mountain roads to Oslo, where Allier and his men were waiting. The rest of the journey had been meticulously planned so as to avoid any intervention by the Germans and the cargo was transported first to London, then on to Paris. Between 16 and 18 March, Frédéric Joliot-Curie finally took possession of the precious liquid. However, the events of May 1940 changed the course of history. The German invasion of France put a stop to the research work being carried out by the French physicists. The drums left Paris for the safety of a strongbox in the Banque de France at Clermont-Ferrand, then were hidden in a cell at the detention centre at Riom in the Auvergne region of central France. In June 1940, as military defeat loomed, Halban and Kowarski took the heavy water to England, where the two men continued their research, while Joliot-Curie opted to remain in Paris.


The subsequent episodes in the heavy water story are quite well-known. The German invasion of Norway gave the Nazis unrestricted access to Norsk Hydro’s production, which prompted the Allied forces to make an – unsuccessful – attempt to destroy the main factory. Eventually a Norwegian patriot managed to sink the ferry carrying the entire stock of heavy water over to German territory.  During the intervening years, the United States took up the UK-based research and their Manhattan programme finally saw the creation of the world’s first atomic bomb.

Jacques Allier, a father of three who had been entirely unprepared for the clandestine role he was called upon to play, gave his timely support to the French Atomic Energy Commission, established in 1945, while also taking up once again his duties at Paribas, becoming a Deputy Director. Several documents from his great adventure, whose contents are worthy of a spy novel, were retained by the Bank and these are today being carefully conserved by the BNP Paribas Group Heritage and Historical Archives department.

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