Every picture tells a story, or so it’s said, and the photo of a smirking Vladimir Putin shaking hands with the Saudi crown prince, Mohammed bin Salman, at the opening game of the men’s football World Cup in Moscow in June 2018 carried a clear warning for the west. The message, for those who cared to heed it: Saudi Arabia, nurtured by the British in the days of empire, defended by the US against Saddam Hussein and Iran, and forgiven its close connections to the 9/11 terror attacks, was no longer the dependent, biddable ally it once was. Prince Mohammed was making new friends. Fabulously wealthy on the back of seemingly limitless oil, pursuing a feisty regional foreign policy in Yemen and Lebanon, building ties with Russia and China, and arrogantly dismissive of western human rights concerns, the Saudis were going their own way. No one symbolises these shifting allegiances more powerfully than the heavily bearded, stockily built heir to the throne, already the country’s de facto ruler and a man who, aged 37, may be expected to rule for the next 50 years. And there he was, in Moscow of all places, bonding chummily with Russia’s killer president. Even then, Putin was leader of a regime under western sanctions for its illegal 2014 annexation of Crimea – an authoritarian thug widely believed responsible for the Salisbury poisonings earlier that same year and other lethal attacks on political rivals, critics and journalists inside Russia and abroad. Yet Mohammed seemed very much at home as the crowd roared and Russia scored. Then, a mere four months later, in October 2018, came the murder in Istanbul of the dissenting Saudi journalist Jamal Khashoggi. For sheer brutality and brazenness, it looked like a state assassination straight out of Putin’s playbook. Joe Biden was not elected US president until two years later. During his campaign he dubbed Saudi Arabia, and by implication its crown prince, a “pariah” after Khashoggi’s murder. As president he froze weapons sales and released intelligence implicating the prince. All of which made his embarrassing U-turn visit to Riyadh in July this year, and his notorious fist-bump with a grinning Mohammed so much more difficult to swallow. Why did Biden do it? It was a question with several possible, equally unsatisfactory answers, and one that has now come back to haunt him. Biden wanted the Saudis and other members of the Organization of the Petroleum Exporting Countries (Opec) to boost, or at least maintain, oil production in order to counter Russia’s use of gas and oil as weapons in the wider east-west struggle over Putin’s Ukraine invasion. He wanted to remind the prince that the US was still a big Middle East player, to encourage closer ties with Israel, to bolster a united front against Iran. He wanted, most of all perhaps, to strike a blow for democracy in what he has cast as a global contest with authoritarianism. More mundanely, Biden wanted to bring down the petrol price for American drivers and consumers, and thereby advance the Democrats’ chances in next month’s midterm congressional elections. He wanted to demonstrate that wily old Joe could fix it. Most, if not all, of Biden’s aims were blown away last week when Opec+, a group that includes Russia, decided to cut oil production by 2m barrels a day, not increase it. The move appears to have genuinely shocked the White House. It was taken as a personal slap in the face for the president. It was humiliating. Almost as bad, it was a stunning win for Putin. Even though the oil cut may not make a vast difference to the global price, it set the Saudis and fellow cartel members against the US and energy-hungry Europe, and on the side of the Russians – a claim the Saudis now energetically deny. Fury has been building up ever since, with Democrats threatening to sanction Opec, suspend defence and security cooperation with Riyadh, freeze arms transfers, withdraw US troops, and launch the thoroughgoing reappraisal of the US-Saudi relationship that Biden promised but never delivered. They’re right to be angry. Although some of these measures are unlikely ever to be implemented, the Saudi-US relationship has long been toxic. A house-cleaning is required. The EU, too, has just found another powerful reason to agree and implement gas and oil price caps, finally end Russian imports and recalibrate relations. Likewise, the UK should undertake a long overdue, full-spectrum re-assessment of ties that frequently raise fundamental ethical questions – as the chancellor, Kwasi Kwarteng, is the latest British public figure to discover. Saudi Arabia’s on-off war in Yemen, and the US and British arms sales that have facilitated it, would be a good starting point for any reassessment. Redoubled attempts to salvage the Iran nuclear deal, which the Saudis distrust, might help bring imperious Riyadh down to earth. The Saudi regime’s mistreatment of women, for example Salma al-Shehab, the Leeds university student jailed for 34 years for her tweets; its use of terrorism courts against its critics; its mass executions; its chronic denial of democratic rights; and its censorship of free speech and personal liberties – these must no longer be tacitly tolerated. Pressure can be brought to bear. Unacceptable, too, is the way the regime is trying to launder its reputation by buying its way into international sport, for example using its petrodollars to take over Newcastle United in the UK football Premier League, and fund prestige golf and boxing tournaments. If Mohammed really prefers the company of the war criminal Putin, and like-minded oppressors and autocrats such as China’s Xi Jinping, he and his regime must pay a high price in terms of their privileged access and support from western leaders and countries. He should think hard what this would mean, for example, for the future defence of his kingdom against Iran’s missiles and drones. Biden had it right the first time. But pariah status needs to mean something. Most important, the US and the western democracies must demonstrate by their actions that the great 21st-century global battle for freedom, democracy, human dignity and international law, exemplified and symbolised by the fight for Ukraine, is too vitally important, too crucial, too epic, to be bartered away for a cheap barrel of oil. Simon Tisdall is a foreign affairs commentator. He has been a foreign leader writer, foreign editor and US editor for the Guardian