Seventy years ago on Thursday, a little after 8.16am Japanese time, the American atomic bomb code-named Little Boy exploded 580 metres above the Japanese city of Hiroshima.
The blast flattened 12 square kilometres of the city and killed more than 135,000 people – 80,000 instantly, the others succumbing to wounds, burns and radiation sickness over the months and years to come.
Three days later, on August 9, a second bomb, Fat Man, visited similar destruction on the city of Nagasaki. On August 14, as America was threatening to drop more bombs, Japan surrendered and the Second World War finally ended.
In his surrender speech, broadcast to a shocked nation the following day, Emperor Hirohito said the enemy now possessed “a new and terrible weapon with the power to destroy many innocent lives and do incalculable damage”.
What they could not possibly have imagined – as only the handful of scientists working on the next-generation nuclear weapons had any idea – was just how much more terrible the nuclear arsenal could become.
Even the bombs of those two fateful days were supposed to have caused far more damage.
Scientifically speaking, the bombs, which used different methods of unleashing the energy that lies at the heart of matter, were experiments and disappointing ones at that.
The Atomic Heritage Foundation records that only 1.38 per cent of the 65 kilograms of uranium in Little Boy actually fissioned and that less than 20 per cent of the 6.1kg of the plutonium in Fat Man was converted into energy.
Even with that, Little Boy unleashed 15 kilotons of power – one kiloton being equal to 1,000 tonnes of TNT explosive – and Fat Man 21 kilotons.
Armed with the data from Hiroshima and Nagasaki, US scientists were already working on the next development – thermonuclear bombs. Within a few years weapons emerged that made Little Boy and Fat Man look like fireworks by comparison.
The most powerful proven weapon to date is the Tsar Bomba, or the King of Bombs, which was test-detonated above the Arctic circle by the USSR in October 1961.
With a yield of 50,000 kilotons, or 50 megatons, it was 3,333 times more powerful than Little Boy and created the largest man-made explosion ever seen.
The USSR joined the nuclear arms race in 1949, followed by the UK in 1952. Next out of the blocks was France (1960), followed by China (1964), India (1974), Pakistan (1998) and North Korea (2006).
Nine nations now have nuclear weapons capability if you include Israel, which is widely suspected of having had bombs since 1966.
According to the Arms Control Association, since Little Boy and Fat Man were dropped over Japan, eight countries have conducted a total of 2,050 test detonations of nuclear weapons – America (1,027), the USSR (715), France (210), China (45), the UK (45), India (3), North Korea (3) and Pakistan (2).
On one level, the US Manhattan Project, which developed the first nuclear weapons, was a stunning scientific achievement. Fuelled by an investment of US$2 billion (Dh7.34bn), equal to about $26bn, and driven forward by some of the finest minds in the world, it fast-forwarded our understanding of nuclear physics, compressing decades of theory and experiments into four short years.
But building the bomb, it turned out, was the easy part. Controlling its use and proliferation tested humankind to the brink of mutually assured destruction during the stand-off years of the Cold War and continues to challenge us today, as the protracted and recently concluded efforts to curb Iran’s nuclear bomb-making ability shows.
The United Nations office for disarmament affairs says that “although nuclear weapons have only been used twice in warfare, about 22,000 reportedly remain in our world today”.
Adding more to the stockpile, argue those determined to stop Iran joining the nuclear club, will make none of us any safer.
It has taken the best part of a decade, 11 UN resolutions and a range of international sanctions and embargoes to reach the Joint Comprehensive Plan of Action finally announced in Vienna last month between Iran and the so-called P5+1 group of nations – China, France, Russia, UK, US and Germany.
Making a bomb these days is a relatively simple matter. All of the technical heavy lifting was done by Robert Oppenheimer and his colleagues in the Manhattan Project.
Now all that is required are a few compliant nuclear physicists, some necessary equipment and a lot of cash.
To the alarm of many observers, while Iran has technically agreed to abandon its ambition to make nuclear weapons, it has not agreed to scrap the extensive infrastructure it has in place that would enable it to make such a weapon.
Instead, in exchange for an end to nuclear-related sanctions and – in eight years – to restrictions governing its access to ballistic missile technologies, it has agreed to concessions.
These include abandoning its production of weapons-grade plutonium, reducing the number of specialist centrifuges it has for the production of enriched uranium and cutting its stockpile of low and medium-enriched uranium, which is enough at the moment to build up to 10 bombs.
For cynics, the ultimate effect of the agreement, which will be policed by the International Atomic Energy Agency, will be only to delay the inevitable.
Without the deal, Iran was thought to have been within two to three months of being able to produce a nuclear weapon.
Even by the White House’s own admission, while the deal “removes the key elements needed to create a bomb”, it only “prolongs Iran’s breakout time from two to three months to one year or more if Iran were to break its commitments”.
If the deal holds, says Timothy Stafford, a nuclear proliferation research analyst for UK defence think tank the Royal United Services Institute, it “could have tremendous importance, especially for the Middle East”.
Certainly, GCC foreign ministers came away from a meeting with US secretary of state John Kerry in Doha on Monday saying the deal “makes this region safer and more stable”, in the words of Qatar’s foreign minister, Khalid Al Attiya.
But by leaving a substantial portion of Iran’s nuclear infrastructure in place, the deal risks “two negative outcomes”, says Mr Stafford.
The first “is that Iran will become a de facto threshold nuclear state once the deal expires”.
“That would greatly enhance its overall military stature, strengthening its ability to intimidate its neighbours.”
The second risk is that the deal will “legitimise the path that Iran has taken, encouraging other states in the region to seek nuclear programmes of their own in the belief that they too will come to be accepted”.
Mr Stafford says that if that scenario unfolds, “it is possible that a nuclear arms race will commence in which many states in the region seek to safeguard their security through the acquisition of nuclear status”.
Such a development “would be tremendously destabilising”, he says.
The Iran agreement is by no means a done deal.
As it stands, the Iran deal is by no means cut and dried. First, it has to pass a congressional vote in mid-September and, as CNN reported on Monday, “anti-deal advocacy groups flush with cash are flooding congressional offices with calls and emails, running ads in national media and employing other campaign-style tactics to sway sceptical lawmakers”.
The contentious deal – so dependent on Iran’s cooperation in allowing “intrusive monitoring” by the IAEA – is of great contrast to the voluntary agreements put in place nine years ago by the UAE as it set about seeking international approval for its adoption of nuclear power for the purely peaceful purpose of generating electricity.
The first of four Korean-made nuclear power plants, at Barakah in Abu Dhabi’s Western Region, is on course to start providing electricity to the national grid by 2017.
In 2008 the UAE, an adherent since 1995 of the Treaty on the Non-Proliferation of Nuclear Weapons, published its Policy on the Evaluation and Potential Development of Peaceful Nuclear Energy.
Among other things, this committed the country’s nascent nuclear programme to working hand in glove with the IAEA to achieve “complete operational transparency” and “the highest standards of non-proliferation”.
The UAE reassured the world by “renouncing an intention to develop a domestic enrichment and reprocessing capability and undertaking to source fuel from reliable and responsible foreign suppliers”.
If such a simple but effective condition had been part of the Iran deal, it might not now be facing political backlash and possible destruction on Capitol Hill.
Instead, Iran has managed to retain the right and the ability to enrich its own uranium.
The result will be continuing uncertainty over Iran’s nuclear ambitions and the ability of the world to contain them.
During a meeting at the Pentagon in May 1945, at which it was decided which Japanese cities would be bombed, Henry L Stimson, president Truman’s secretary of war, was struck by the enormity of the force his nation was about to unleash on the world.
The atomic bomb, he wrote in his notes of the meeting, would either “destroy or perfect international civilisation” and be either a “Frankenstein or a means for world peace”.
Seventy years later, on the eve of the anniversary of the bombing of Hiroshima, the jury is still out.