It was a year dominated by a handful of powerful men whose actions frequently imperilled the lives of millions and jeopardised the future safety and resilience of the planet. America’s Donald Trump, Russia’s Vladimir Putin, China’s Xi Jinping, and a rogues’ gallery of like-minded, second-tier authoritarian figures around the world used their positions to advance national and personal interests at the expense of universal democratic, legal, environmental and human rights.

The arbitrary behaviour of these powerful men produced strange and daunting paradoxes. The American economy expanded, even as a US-China protectionist tariff war restricted global free trade. Europe marked the 100th anniversary of “the war to end all wars” amid fears of new conflict with Russia. Nuclear-armed states shredded key arms control pacts while ostracised Iran fought to save one. The furore over the murder of a lone Saudi journalist created more headlines than multiple human tragedies in Syria, Yemen and Afghanistan.

Peace broke out between North and South Korea, Ethiopia and Eritrea, in South Sudan, and in Spain’s Basque country, where ETA disbanded – but Palestinians and Israelis traded harsh blows, marking 70 years of strife. The climate change crisis was better understood than ever. Yet the international response was handicapped by political divisions, rendered more febrile by a 12-year scientific deadline to save the planet, reported worldwide declines in flora and fauna, and extreme weather events such as California’s wildfires.

On a more optimistic note, in Malaysia, the good guys won for a change, toppling a corrupt leader and proving that hoards of jewellery and Hermès handbags do not guarantee happiness. The #MeToo movement continued its powerful backlash against predatory and domineering males. A black American actor married a reddish English prince at Windsor Castle. The England football team surprised everybody by reaching the World Cup semi-finals. And Canadians, perhaps hoping to get away from it all, legalised cannabis.

Adventures in crazytown

Donald Trump again dominated the news agenda in 2018, mostly for the wrong reasons. His intolerance of criticism, arbitrary decision-making and bending of the truth set the tone for anti-democratic, authoritarian strongmen around the world. Trump became America’s first “rogue president”.

Trump’s sinister attempts to intimidate what he called the “fake news” media raised fears about democracy and free speech. He used his Twitter commentaries – random, inaccurate and sometimes libellous – to distract attention from his failings, such as his enduring problem with women.

When Trump’s supreme court pick, Brett Kavanaugh, was accused of sexual misconduct during Senate confirmation hearings, Trump responded by denigrating the principal accuser, Christine Blasey Ford. His blatant misogyny polarised the country – a trademark Trump effect.

Christine Blasey Ford is sworn in before testifying the Senate judiciary committee Photograph: Win McNamee/Getty Images

Trump himself faced multiple claims of sexual misconduct. Ex-porn star Stormy Daniels provoked embarrassment and derision with an unflattering description of the presidential penis. Trump’s legal troubles deepened as his former personal attorney, Michael Cohen, talked to prosecutors and confessed to a string of crimes, including campaign finance violations that directly implicated the president. Trump continued to accuse the special counsel, Robert Mueller, of conducting a witch-hunt – but did not dare fire him. By year’s end, Mueller’s net seemed to be closing.

The US midterm elections handed a sharp rebuke to Trump. The Democrats’ “blue tsunami” of 40 gains in the House of Representatives suggested congressional scrutiny of Trump’s activities will increase exponentially in 2019. Trump’s cynical pre-poll claim that a Central American migrant caravan threatened national security failed to stop the rout.

By year’s end fewer than half of all Americans (40%) approved of his job performance.

The impunity of Putin

In Russia, Vladimir Putin was re-elected president in a rigged poll that allowed no other result. Putin ensured his domestic dominance by hounding critics such as opposition leader Alexei Navalny. He used Russia’s hosting of the football World Cup in June to further entrench his position. Putin nevertheless faced nationwide resistance over state pension changes, and his popularity fell amid mutterings about high-level corruption.

Putin purposefully projected Russian power abroad, conducting a large military exercise with China, probing Nato’s defences in the Baltic and North Atlantic, and using disinformation campaigns to influence elections in Europe and the Balkans. Russia’s military seized Ukrainian naval vessels off Crimea, sparking fears of a war involving Nato. It also helped Syria’s dictator, Bashar al-Assad, regain control of most of the country.

Trump’s fawning attitude to Putin, intensified speculation that the Kremlin holds compromising information about him. Even after Russia was proved to have mounted a chemical weapons assassination plot in southern England, and was punished with additional western sanctions, Trump avoided direct criticism. For his part, Putin ridiculed his accusers.

Xi Jinping for ever

China’s leader consolidated his hold on power following a decision by the National People’s Congress in March to abolish terms limits – effectively appointing him president-for-life. The Communist party tightened its control over civil society groups, the media, the internet, and academic and religious institutions. Challenging the government became a more perilous activity than ever.

Xi Jinping at the 13th National People’s Congress in Beijing in March. Photograph: Roman Pilipey/EPA

Xi’s zero tolerance of dissent was symbolised by the harsh treatment of Muslim Uighurs in western Xinjiang province. Reports detailed mass incarcerations in “re-education” centres, ostensibly to contain a threat from Islamist extremism. Human rights defenders and pro-democracy activists suffered repression in Hong Kong.

Like Putin, Xi stepped up an aggressive drive to expand China’s global reach. The militarisation of several artificial islands in the South China Sea was completed. Xi tightened Beijing’s diplomatic siege of Taiwan. These moves produced dangerous confrontations with US forces conducting “freedom of navigation” patrols.

The other dictators and demagogues

The top-down trend favouring “strongman” leadership accelerated around the world. In Brazil, a hard-right nationalist, Jair Bolsonaro, survived a knife attack to win the presidency and was embraced as a kindred spirit by Trump. Bolsonaro’s focus on development intensified worries about the despoliation of the Amazon.

A UN report demanded the Myanmar junta of General Min Aung Hlaing be investigated for genocide and crimes against humanity over its persecution of Rohingya Muslims.In Bangkok, an authoritarian ex-general, Prayuth Chan-ocha, prepared to oversee elections – amid fears the polls would be rigged or postponed again.

A Myanmar border guard police stands guard near a fence of Rohingya refugees. Photograph: Nyein Chan Naing/EPA

In Venezuela, Nicolás Maduro, Hugo Chávez’s incompetent successor, presided over large-scale misery. Millions fled to neighbouring countries to escape deepening poverty, terrifying crime rates and political misrule. In the Philippines, Rodrigo Duterte, emulating Trump’s America First rhetoric, admitted he had ordered extrajudicial killings.

Abdel Fatah al-Sisi finally extinguished the hopes of the 2011 Arab Spring. He was “re-elected” Egypt’s president with a Mubarak-style 97% of the vote after all credible opponents were jailed, harassed or pressured to withdraw. In Turkey, Recep Tayyip Erdoğan, setting what he called “an example for the rest of the world”, bullied his way to another presidential term and sweeping extra powers.

In North Korea, the country’s ruthless, ever-grinning dictator, Kim Jong-un, was bolstered by a summit with Trump in Singapore. Trump claimed a breakthrough on nuclear disarmament – but in practice, Kim stuck to his guns.

The year saw the emergence into full public view of another autocratic Trump ally – Mohammed bin Salman, the Saudi crown prince. Salman had presented himself as liberal reformer, graciously allowing women to drive. But then came the murder in the Saudi consulate in Istanbul of a leading critic, US-based journalist Jamal Khashoggi. Turkey and the CIA claimed to have conclusive evidence that Salman ordered the killing.

The claim was furiously denied. But Prince Mohammed’s credibility lay in tatters. Trump worked shamelessly to defend his protege, but his inept White House statement succeeded only in appearing to condone the murder.

The Saudi crown prince symbolised the type of unscrupulous, authoritarian and anti-democratic leader who came to the fore around the world in 2018. Their emergence was an augury of an even more dangerous development: a breakdown in international law and the slow collapse of the global order.