During the Cold War the threat of nuclear war was held in check by a perilous doctrine dubbed ‘Mutually Assured Destruction’. The idea behind this was that, because both sides maintained huge stockpiles of nuclear weapons, neither would dare attack the other, for to do so would be suicidal.
Rather aptly, this theory was abbreviated to ‘MAD’.
Despite the principle behind MAD, numerous cold war bunkers were still built across London and other parts of the country as a last resort in order to protect the government in the event of war.
Incredible as it may sound, the key theory that sparked the development of these terrifying weapons occurred one damp morning in London’s leafy, central area of Bloomsbury; conceived within the great mind of a 1930s Bloomsbury resident called Leo Szilard.
The early life of Leo Szilard
Born in Budapest, Hungary in 1898, Leo Szilard (pronounced as “sil-ahrd”) was a brilliant Jewish physicist and inventor who excelled at mathematics from an early age.
Towards the end of the Great War Leo was enlisted in the army. Before seeing action however he contracted influenza. In hindsight this likely saved his life as most of the soldiers from his battalion were killed.
After WWI Leo had ambitions of studying engineering. However, he was barred from doing so due to anti-Semitic policies.
This led him to move to Berlin where he turned his mind to physics and befriended Albert Einstein.
Leo moves to Bloomsbury, London
Leo flourished in Germany during the era of the Weimar Republic but immediately recognised the danger when Hitler gained power in 1933. He quickly made plans to flee the country and encouraged fellow Jews to do so too. Leo made a home for himself in London.
When Leo arrived in London he had sufficient funds to support himself. However, he didn’t forget his friends and colleagues and he helped to establish the Academic Assistance Council (now known as the Council for At-Risk Academics) which helped to secure work and accommodation for Jewish refugees at Burlington House, Piccadilly.
This choice was based on Leo’s philosophy that “there is no place as good to think as a bathtub” and, back then, the Imperial was famed for its steaming Turkish baths.
Sadly these were demolished when the Imperial was rebuilt in the 1960s, although a ghost sign for the baths can still be spotted in the pavement at the end of Guildford Street, outside a branch of Pret a Manger.
Leo's Eureka Moment in the Heart of Bloomsbury
On the morning of September 12th 1933 Leo breakfasted and took his customary bath before heading to the Imperial’s lobby where he obtained a copy of The Times.
In the newspaper, he found a report on a scientific conference which had taken place the day before where renowned scientist Ernest Rutherford had rubbished the idea that power could be gained from atoms, stating that anyone who believed so was “talking moonshine.”
This opinion bothered Leo; he was sure Rutherford was wrong and decided to go for a walk to chew the idea over.
Just outside the Imperial Hotel, on the junction of Russell Square and Southampton Row, Leo paused at a set of traffic lights. As they turned green his Eureka moment came:
“It suddenly occurred to me that if we could find an element which is split by neutrons and which would emit two neutrons when it absorbs one neutron, such an element, if assembled in sufficiently large mass, could sustain a nuclear chain reaction.”
Leo had effectively worked out the basis for creating nuclear energy, a concept which would soon change the world. As historian Richard Rhodes would later describe:
“The stoplight changed to green. Szilard stepped off the curb. As he crossed the street time cracked open before him and he saw a way to the future, death into the world and all our woes, the shape of things to come.”
A dreadful secret
Although Leo knew his theory would prove Rutherford wrong, he was also bitterly aware that the concept he’d envisioned could be weaponised.
His mind therefore had suddenly been laden with a dreadful burden. The thought of such knowledge being leaked to the Nazis horrified him and he initially opted to keep his breakthrough to himself.
Leo busied himself with study and, in 1934, took up a post at St Bartholomew’s Hospital, West Smithfield where he conducted experiments with radioactive isotopes.
As the 1930s progressed however and the Nazis continued to gain strength, Leo decided to patent his chain reaction theory, an action which technically granted him copyright on the atomic bomb.
To ensure it remained secret however, he entrusted this patent- which described “neutron induced chain reactions to create explosions” to the British Admiralty.
Leo's theory becomes reality
In the late 1930s Leo moved to the United States where, growing ever more concerned of the Nazi’s suspected scientific advances, he wrote an urgent letter to President Roosevelt warning of a “new phenomenon” which could “lead to the construction of bombs.”
This was signed by Leo’s friend Albert Einstein and received by Roosevelt in August 1939, just one month before WWII erupted in Europe.
This correspondence led to the formation of the ‘Manhattan Project’; the USA’s top secret programme to build the atomic bomb.
Although Leo worked worked on the project the idea of dropping these weapons on cities horrified him and he implored President Truman to demonstrate their power before unleashing them.
His pleas were ignored and in August 1945 the nuclear flashes over Hiroshima and Nagasaki killed at least 129,000 people in an instant, bringing the theory that had occurred to Leo on Russell Square 12 years before to its disturbing climax.
After WWII Leo became a dedicated peace campaigner, speaking out against the weapons he had reluctantly helped to create.
Leo also pioneered modern chemotherapy techniques which he successfully tested upon himself after contracting bladder cancer. He passed away in 1964, aged 66, his incredible discovery that day in Bloomsbury having changed the world forever.
Read the rest of my Cold War London series:
Part one: London’s Cold War Spy Locations
Part two: The Umbrella Assassination
Part three: London’s Cold War Bunkers
And make sure you check out my top picks from the National Archives’ excellent exhibition: ‘Protect and Survive: Britain’s Cold War Revealed’