For the second time since Saudi Arabia and the UAE began bombing Yemen, the world’s biggest arms fair came to London last month. The biennial Defence and Security Equipment International Fair (DSEI) was denounced by both the mayor of London and Newham Council. The Court of Appeal judged in June that ministers had for years been illegally signing export licences for arms to be used in Yemen. That didn’t stop the Ministry of Defence inviting Saudi Arabia and the UAE, which buy most of Britain’s arms exports, to DSEI 2019.

At the ExCeL exhibition centre in Canning Town, 1700 companies were displaying their wares. British soldiers – ‘military escort officers’ – looked after delegations from all over the world. They took them to their hotels and they took them shopping. One escort told me that the Angolans were on the hunt for helicopters and the Egyptians were after surveillance equipment. A delegation from the UAE lingered at the stall of the Italian firm Cristanini: a woman in a camouflage cocktail dress and knee-high boots stood in front of a display of decontamination equipment, for use after chemical or biological attacks.

‘Strike with creativity’ was emblazoned on the wall above the Raytheon stall. Raytheon manufactures its Paveway laser-guided bombs in the US and at factories in Harlow and Glenrothes in the UK. Paveway fragments have been found in the wreckage of schools, hospitals and markets across Yemen. One was used for an attack on a wedding in April 2018, killing 18 people, mostly children. ‘Body parts were on trees and rocks and people tried to collect as many of them as possible,’ one of the guests said. ‘The remaining parts were eaten by dogs.’

When I mentioned the Paveway, the Raytheon salesman clammed up and ushered me towards his colleague in the communications department. He answered my questions on the use of Raytheon’s weapons in Yemen with corporate boilerplate: ‘We rely on the government to make assessments.’ I asked how he felt about his company’s involvement in the deaths of civilians in Yemen. ‘I can tell you I certainly didn’t kill anybody,’ he said irritably, before correcting himself. ‘I’d like to thank you for your time,’ he said, and rushed away to close himself behind a door marked ‘staff only’.

BAE Systems, the UK’s largest arms company, occupied an enormous area of the conference floor. BAE – ‘Advantage where it counts’ – builds weapons for the UK military but is also commissioned by the MoD to supply the Saudi Royal Air Force with planes, bombs and more than six thousand engineers to keep the sorties over Yemen going. BAE staff were surprisingly willing to discuss the reality of the business. One compared the company’s sales to Saudi Arabia with the US gun trade: ‘It’s not our problem after we sell it,’ he told me. ‘I didn’t pull the trigger.’ Another BAE representative told me that the company was in ‘an ugly situation’. ‘Something like a hundred thousand civilians have been killed,’ he said of the Saudi-led bombing campaign of Yemen. ‘No one is claiming that we are deliberately targeting civilians. OK, fine. You’ve still killed a hundred thousand though … Do you feel better because you didn’t directly target them? Maybe a little better but they’re still dead.’

Alan Clark, Margaret Thatcher’s defence minister in the late 1980s, wrote in his diaries that Britain’s export controls were ‘high sounding’ but ‘so imprecise and so obviously drafted with the objective of flexibility in either direction – elasticity, shall I say – as to make them fair game [and] elusive of definition’. But in office, ministers maintain the charade. ‘This country operates one of the toughest control regimes in the world,’ Boris Johnson, then foreign secretary, told Parliament in 2016. ‘The most relevant test is whether there is a clear risk of those weapons being used in a serious violation of international humanitarian law.’ In June this year, the courts found that ministers including Johnson, Liam Fox, Sajid Javid and Jeremy Hunt had in fact not been considering alleged IHL violations at all when signing off arms export licences to Saudi Arabia, in contravention of domestic law. But the judgment hasn’t altered the dynamics of the British-backed air war.

According to Rachael Gordon, BAE’s communications manager, the company has told its investors that it can continue to meet Saudi orders for planes and bombs. Despite the Court of Appeal’s judgment that ministers had acted unlawfully, it did not actually order the government to ban sales. Instead, a messy compromise was reached: new licences would be prohibited but existing licences are still valid, pending an internal government review – currently being conducted by the international trade secretary, Liz Truss – or a case in the Supreme Court. Privately, ministers say that they expect existing licences to remain in force under Truss’s review, and the government is appealing to the Supreme Court to lift the ban on new licences. Truss’s department has already broken the court’s order, signing off numerous arms export licences – ‘in error’, she told Parliament. Keith Vaz (who was born in Aden) asked if the death certificates of civilians killed by illegally licensed British arms exports should read ‘death by administrative error’.

Outside the exhibition’s VIP area, masseurs had set up shop. One told me that she works at all sorts of conferences – ‘beauty, sportswear, kitchens’ – but the bodies of DSEI attendees are especially tense. ‘These people are blocked,’ she said, pressing her thumb between my shoulder blades. ‘This is where the energy doesn’t pass … They don’t care about themselves and they don’t have time for the world.’

Jonathan Newman, a social anthropologist studying the relationship between markets and ethics in the defence sector, told me that ‘these people don’t talk to each other about the ethics of their trade. Ethics are either deferred onto government regulations or processed privately with family and friends. Everyone here is just chasing numbers. We have become number people. Some of the worst horrors of the last hundred years have been projects driven by work targets.’

Last March, three months before the courts found that his department had been routinely breaking the law by approving arms licences to Saudi Arabia, a senior manager at the Export Control Joint Unit compared himself to Adolf Eichmann. ‘I’m just doing what I’m told,’ he said.

At Dillon Aero I was shown a 3000-rounds-per-minute Gatling gun. ‘It’s to kill bad guys,’ the ex-military salesman said. The Brazilian firm Condor is marketing electric shock equipment. ‘It’s for the people in the favelas,’ the salesman said. ‘They come down and cause trouble.’ At the Calder Defence stall, I failed to win £50 of Marks and Spencer vouchers by guessing the number of bullets in a jar.

‘Ready for today’s mission,’ said the marketing slogan on the back of the fair’s floor plan, ‘prepared for tomorrow’s threat.’ What is today's mission? According to Newman, the industry is self-serving, creating new insecurities so that it can sell new technological solutions. ‘It’s an endlessly sustainable bottom line. The design and engineering capacity of this sector is astonishing. If their creative intelligence was matched at a business and political level, they could probably fund and engineer fresh drinking water for the world in a year. And that could reduce the threat of war, but in their current thinking, threats are integral to sector growth.’

In order to sell their products, defence companies need to sell threats. At the BAE annual meeting in June, the chairman, Roger Carr, spoke gravely of Yemeni terrorists hiding in the civilian population, and Saudi Arabia’s duty to protect its citizens. ‘Our belief is that if you supply first class equipment you are the encouragement for people to stop fighting,’ he told shareholders. This is peddling war as peace. If Britain’s £23 billion defence sector increased global security, it would not be growing so fast. But there appears no end in sight for violent innovation.