When I first went to Hiroshima in 1967, the shadow on the steps was still there. It was an almost perfect impression of a human being at ease: legs splayed, back bent, one hand by her side as she sat waiting for a bank to open. At a quarter past eight on the morning of 6 August, 1945, she and her silhouette were burned into the granite. I stared at the shadow for an hour or more, unforgettably. When I returned many years later, it was gone: taken away, ‘disappeared’, a political embarrassment.

Another shadow now looms over all of us. This film, The Coming War on China, is a warning that nuclear war is not only imaginable, but a ‘contingency’, says the Pentagon. The greatest build-up of Nato military forces since the Second World War is under way on the western borders of Russia. On the other side of the world, the rise of China as the world’s second economic power is viewed in Washington as another ‘threat’ to American dominance.

To counter this, in 2011, President Obama announced a ‘pivot to Asia’, which meant that almost two-thirds of all US naval forces would be transferred to Asia and the Pacific, their weapons aimed at China.

Today, some 400 American military bases encircle China with missiles, bombers, warships and nuclear weapons. They form an arc from Australia north through the Pacific to Japan, Korea and across Eurasia to Afghanistan and India. It is, says one US strategist, ‘the perfect noose’.

In secrecy, the biggest single American-run air-sea military exercise in recent years – known as Talisman Sabre – has rehearsed an Air-Sea Battle Plan, blocking sea lanes in the Straits of Malacca, cutting off China’s access to oil, gas and other raw materials from the Middle East and Africa.

It is largely this fear of an economic blockade that has seen China building airstrips on disputed islands and reefs in the South China Sea. Last year, Chinese nuclear forces were reportedly upgraded from low to high alert.

This is not news, or it is news distorted or buried. Instead, there is a familiar drumbeat identifying a new enemy: a restoration of the psychology of fear that embedded public consciousness for most of the 20th century. The aim of The Coming War on China is to help break the silence. As the centenaries of the First World War presently remind us, horrific conflict can begin all too easily. The difference today is nuclear.

This is my 60th film, the majority for ITV and including those made for the cinema. Filmed on five potential frontlines across Asia and the Pacific during almost two years, the story is told in chapters that connect a secret and ‘forgotten’ past to the rapacious actions of great power today and to an inspiring popular resistance, of which little is known in the West.

Chapter one, ‘The secret of the Marshall Islands’, describes a secret programme – Project 4.1 – that turned these Pacific islanders into guinea pigs for the development of nuclear weapons. Once known as the Last Paradise, the Marshalls and their indigenous people were subjected to the equivalent of a Hiroshima bomb exploded every day for twelve years.

Of all the places of upheaval I have reported from, I have not experienced anything quite like Bikini atoll. In the emerald lagoon where the US exploded a hydrogen bomb called Bravo in 1954, there is a vast black hole, a void in which an entire island was vaporised. Bikini’s people have never returned. The food is unsafe to eat and the water unsafe to drink. There are no birds and no natural sounds. Our shoes registered ‘leave now’ on a Geiger counter. The US Department of Energy comes regularly to measure its mutations; there is a radioactive market garden and palms planted in surreal grid formation. The experiment never ends.

“We were screaming,” Betty Edmond told me. “I tried to hide behind my parents.” Lemoyo Abon said, “We thought it must be another war or the end of the world.” These women, and others we filmed, were children on the nearby island of Rongelap when Bravo irradiated them. Described in long-forgotten archive footage as ‘amenable savages’, most of the survivors have had thyroid and other cancers and have received little compensation.

Today, they live in the shadow of the Ronald Reagan Missile Test Site, a huge and secretive US base on the largest island, Kwajalein, where they are again subjected to the testing of weapons of mass destruction. Here, the US Air Force fires missiles into the lagoon at a cost of $100 million a shot. A missile test is announced with a few sentences in the Marshall Islands Journal, if it all; then the sky lights up and people fall ill, ‘mysteriously’. Many of the fish are unsafe to eat.

Like a tableau of expatriate suburbia, the base’s golf course is watered by dispossessed islanders who are ferried to work from their slums across the bay, and back again, at dusk. The base commands the Pacific all the way to Asia and was built, says official archive film, ‘to protect America from communist China’.

Crossing the Pacific, I arrived in Shanghai for the first time in more than a generation. Then, Mao Zedong had recently died, and the cities seemed dark places, in which foreboding and expectation competed. Within a few years, Deng Xiopeng, the ‘man who changed China’, was the ‘paramount leader’. Nothing prepared me for the astonishing changes today.

‘I make the joke, ‘ says the Shanghai social scientist Eric Li in the film, ‘In America you can change political parties, but you can’t change the policies. In China you cannot change the party, but you can change policies. The political changes that have taken place in China this past 66 years have been wider and broader and greater than probably any other major country in living memory’.

This is one of a number of views from within China’s new and confident political class that make a rare appearance in a western documentary. In Western ‘media culture’, these revealing voices are generally excluded, because they do not fit the received wisdom, a form of censorship by omission. Like the imperial Edwardians, we in the West still prefer to see Asia in terms of its usefulness or hostility to us, or its failings by our standards, which we promote as enlightened. The Coming War on China is about the imposition of this sense of superiority and its reckless power.

Using some remarkable archive footage, the film touches on the American cult of ‘exceptionalism’ that influences America’s view of humanity and ignites its wars. Since 9/11, the US has spent $5 trillion on aggressive wars, according to a study by Brown University. The current flight of 12 million refugees from at least four countries is one consequence.

Andrew Krepinevich, a former Pentagon war planner and the influential author of war games against China, wants to ‘punish’ China for extending its defences to the South China Sea. He advocates seeding the ocean with sea mines, sending in special forces and enforcing a naval blockade. ‘Our first president, George Washington, said if you want peace, prepare for war.’ This speaks for a view dominant in political Washington.

The Japanese island of Okinawa has 32 US military installations, from which Korea, Vietnam, Afghanistan and Iraq were attacked. The principal target now is China. There are military aircraft constantly in the sky, sometimes crashing into homes and schools. A hugely popular Okinawan movement against this repressive occupation is an extraordinary expression of how ordinary people can peacefully take on a military giant, and begin to win (by electing Japan’s first anti-base governor). One of their leaders is Fumiko Shimabukuro, aged 87, herself a survivor of the world war and perhaps the most resilient human being I have filmed.

Lying at the southern tip of Korea is Jeju Island, where a proxy US base has been recently completed. Nuclear submarines will dock here, along with the latest Aegis missile destroyers, less than 400 miles across the horizon from Shanghai. A people’s resistance has been an everyday presence in the villages around this base for almost a decade. They are indefatigable; priests block the gates by staging a twice-daily mass, backed by people from all over Asia and the world. It is these voices that make the lessons of Hiroshima and Bikini more urgent than ever. ‘We offer a choice,’ says Fukimo, ‘Silence or life’.

John Pilger