Did it really happen? Was it really so bad? Is it true that they were so unprepared? These are the questions I have heard the past few months in connection with the stunning success of the miniseries Chernobyl. It brought to life the tragedy of people who lived through, were affected by and, yes, caused the world’s worst nuclear disaster.

My book Chernobyl: History of a Tragedy, published in May 2018, one year before the broadcast of the miniseries, tells the story of the disaster on the basis of recently released archival documents, which I checked against people’s diaries, memoirs and interviews. Thus, on the factual level, I can provide some answers to the accuracy of the miniseries. But inquiries I’ve received in the past few months also made me think about the bigger question of what is true in our current understanding of the Chernobyl disaster, its causes, development and consequences.

On the plus side, we are now better informed but want to know much more, and theoretically the openness of the debate should help. The irony is that technological progress creates unlimited possibilities for tampering with today’s “openness”, making it even more difficult to establish the truth about Chernobyl and assess the benefits and drawbacks of nuclear power. What the public thinks about Chernobyl and nuclear power is extremely important, since it is the public that votes in elections and influences political decisions on matters of energy and ecology. But the arrival of the age of “alternative facts” and “post-truth” makes informed debate extremely difficult. Uninformed opinion flourishes, as do conspiracy theories, with the result that science finds itself under attack, unable to win a fight without rules in a world shaped by Twitter.

Let’s consider a couple of examples of the ease with which conspiracy vitiates meaningful debate about Chernobyl and the pros and cons of nuclear energy. In 2015, The Russian Woodpecker, a documentary that promotes an “alternative” version of the Chernobyl disaster, received a grand jury prize at the Sundance film festival, lending international recognition and legitimacy to what is in essence a conspiracy theory. The film introduces the view that the explosion had something to do with the super-secret Soviet Duga radar system, built a few kilometres away from the plant and abandoned after the disaster. I cannot count the number of questions raised about the possibility that the Soviet military blew up the reactor.

The Ukrainian artist Fedor Alexandrovich, star of the 2015 documentary, The Russian Woodpecker. Photograph: Sundance

Then there’s a new Chernobyl miniseries announced by the Russian television station NTV, which points a finger at CIA operatives. The Russian production is first and foremost a response to the enormous success of the HBO/Sky drama, which received substantial but mostly negative attention in Russia. Many are upset that it was the British and Americans, not the Russians, who were the first to tell the world a story that the Russians consider their own and in such epic fashion.

Others saw the production as an attack on the prestige of the Russian state in its Soviet incarnation or as a western plot to undermine Rosatom, the Russian monopoly enterprise producing reactors and equipment for the nuclear industry, and its prospects of obtaining lucrative contracts outside Russia.

While the effort of this miniseries to pin the blame for the disaster on the CIA strikes one as bizarre, there is little doubt that it will gain currency in Russia. The KGB seriously considered such a possibility immediately after the explosion and attacks on the west for political exploitation of the disaster were commonplace in the Soviet media for months afterwards.

Mikhail Gorbachev, centre, visits the Chernobyl nuclear power plant in February 1989. Photograph: V Samokhotsky/AFP/Getty Images

Ironically, Mikhail Gorbachev, the father of glasnost, led the way in anti-western propaganda at the time. Almost two-thirds of his first address to the country on the catastrophe, which he delivered in mid-May 1986, consisted of attacks on the US and its western allies. It would appear that when it comes to the nature of debate in Russia, we have come full circle. In Moscow today, as in 1986, before glasnost and perestroika, the main values to be promoted and defended are the prestige of the state and its nuclear programme, while the main enemy from whom those values must be protected is once again the west.

The critics of the HBO/Sky series point to the inaccuracies in its portrayals of the individual episodes and characters as well as misrepresentation of some of the realities of Soviet life. They are often correct. But the creators did a much better job at accurately recreating and visualising that reality than any other western and most of the post-Soviet TV productions. They grasped the big truth about the political and social conditions that caused Chernobyl better than any other film-makers before them, contributing to our common understanding of not only the story of Chernobyl but also the challenges we face together in dealing with the nuclear energy.

Today, we are witnessing a revolt against globalisation and a revival of populism and nationalism reminiscent of interwar Europe. The “America first” sentiment in the US, Brexit in the UK and Putinism in Russia are aspects of a major shift away from the universal and back to the particular. Many look at the world from ever more narrow vantage points, geographic, political, social and cultural. But nuclear disasters recognise no international, social or cultural borders, affecting people and countries that had nothing to do with a plant’s construction, and their consequences stay with us for ever –the half-life of the plutonium 239 released by Chernobyl is 24,000 years.

What’s essential about Chernobyl is that we cannot live with conflicting “truths” about the same event, created and disseminated within isolated national, social or cultural spaces. It was just such “truths” that created the monstrous Chernobyl disaster: authoritarian control over economy and society, lack of free discussion and dissemination of scientific information, and disregard for human life and health in the pursuit of allegedly higher economic or political goals, to name a few. Improving reactors and making them safer is important but not sufficient.

We must reach agreement on the political, economic and social conditions that produced disaster in the past if we are to prevent future catastrophes that may threaten the existence of humankind as a whole.

• This article is based, in part, on last week’s Baillie Gifford Prize Lecture at Edinburgh Books Festival