Kieran Doherty / Reuters

In the Gothic grandeur of London’s ancient Guildhall, the great and the good of trans-Atlantic conservatism gathered to search for the conviction they once had.

The conference was in honor of Margaret Thatcher, 40 years after her era-defining election in 1979 as Britain’s first female prime minister. The event was slated as an opportunity to examine the “special relationship” between Britain and the United States and what relevance—if any—it still had in the era of Donald Trump, Boris Johnson, and Brexit. It was supposed to be about the future, but in reality was more like a wake for the certainties of the past. The confidence had gone.

Thatcher took over as prime minister at a time of crisis in the U.K. Britain was the sick man of Europe: poor and seemingly ungovernable, a country in terminal decline according to the Tory caricature. An outsider—the daughter of a grocer—she radicalized the Conservative Party and the country, rising to the top almost accidentally as the only figure prepared to challenge the incumbent, Ted Heath. After defying the odds to win the leadership, she spent a transformative decade at 10 Downing Street, ripping up the postwar consensus with a brute Tory radicalism that divides Britain to this day. Britain was remade as a low-tax, service-sector economy, doing away with the old industries of the north and letting the City of London explode. She presided over the last unequivocal British military victory and reenergized the alliance with the United States.

Forty years on, Britain once again appears divided and ungovernable, hurtling toward another decisive moment in its history, just as it did at the dawn of the 1980s. But what should the party do now—on the cusp of Brexit ? Who is the enemy? And where is a new Thatcher?

All around, the old certainties of the postwar era are crumbling: Russia is back, but changed and leading the fight against Western liberalism; China is everywhere, but as friend or foe it’s hard to tell; and even the United States, that once reliable pole, is now suddenly shaky, flirting with Vladimir Putin, bickering with Europe, and worryingly soft on NATO.

Maurice Saatchi, a Conservative peer and influential Thatcher acolyte, opened the conference by warning the audience that politics could never be a science: It is chaotic, messy, and subjective. Opinions and convictions are the currency. “In politics,” though, he said, “once you express opinions or beliefs, or attempt to offer explanations or descriptions or forecasts, then error, doubt, and uncertainty come to the fore.” It was a jarring message for the audience that had come to be retold the old certainties of 1979. Where had they gone?

Thatcher, who remained prime minister for 11 years, until 1990, continues to hang heavy over British politics, though in a very different fashion from her Cold War partner, Ronald Reagan, in the United States. Unlike Reagan, she remains a toxic presence in large swaths of the country where the economic revolution she ushered in has left deep scars that have never quite healed.

Under David Cameron’s 11-year leadership of the Conservative Party (including six years as prime minister) that ended in June 2016, after the Brexit vote, being a “Thatcherite” was not a badge of honor that many would choose to wear. It was too harsh, too divisive, too Tory. Thirteen years of Labour government had forced conservatism to change—to be more socially liberal and “compassionate,” in touch with Middle England’s perceived modern values.

It worked for a while, ushering in Cameron’s premiership. Yet his gamble to promise a referendum on Britain’s membership in the European Union upended everything, leaving the Conservative Party—and the country—divided and directionless.

While Thatcher has not been in vogue, she has remained ever present. Her negotiating success in the 1980s, winning an annual rebate on Britain’s EU membership fees, has become the benchmark no British prime minister has been able to meet. Cameron’s attempted renegotiation of Britain’s membership in the EU never met the bar the country demanded. When it came to Theresa May’s turn to negotiate an exit package, that too failed the Thatcher test: May, it was quickly decided, had been bullied by Europe in a way her female predecessor would never have stood for. A five-part BBC documentary on Thatcher’s legacy was aired to coincide with the anniversary of her rise to power, reinforcing her status as a giant, good or ill.

Now, as Britain peers over the cliff edge of a no-deal Brexit, the radicalism Thatcher offered in 1979 stands as the test of virility for the next generation of Tory-leadership contenders: Boris Johnson or Jeremy Hunt. What would Thatcher do today? Would she have been a remainer or a leaver? It is notable that the only other leader who sparks such claims of ownership is Winston Churchill.

Anne Applebaum, a historian and professor at the London School of Economics who chaired one of the panels at the conference, told me the lack of conviction in the Tory party was at the root of the country’s crisis today. “It explains why nostalgia is their central message, and it also helps you understand … some of the appeal Brexit has to Tory-party members,” she said.

Brexit was fundamentally about making Britain great again—like it was under Thatcher.

“It’s a particularly bad Tory-party disease,” Applebaum added. “It wasn’t just that Britain and America were important countries in the 1990s … it was that the conservative parties—the Republican Party and Tory party—had created the set of ideas that the rest of the world followed.” This victory of ideas gave the Tory party its mission. That has gone. “The collapse of Thatcherite certainty is the cause of the current crisis,” Applebaum said.

What, for instance, should today’s Tory party do about Trump and Putin, two leaders who, to varying degrees, oppose the social liberalism that has developed in the Western world since the 1960s? If the new global divide is culture, not economics, whose side is the Conservative Party on?

Back at the conference, the focus was on economics and geopolitics rather than culture. This is the terrain, after all, where the Tories feel most comfortable. Onstage, a series of leading Conservative politicians and commentators assessed what was needed to drag the country out of the current morass. Michael Fallon, a former defense secretary who is backing Johnson for the leadership, called for calm and urged the United States to stick with Britain. “Don’t give up on us,” he said. Allister Heath, the conservative editor of The Sunday Telegraph, said referenda were needed to bypass the elites and return to the “popular conservatism” of the 1980s. Ryan Streeter, a Republican strategist, said the U.S. and Britain needed to rediscover the “dynamism” of the 1980s.

But it was not only on domestic matters where the certainty had gone. In the set-piece event of the day, a conversation with Niall Ferguson, the conservative historian, and George Osborne, the former chancellor, consensus could not even be found on where Britain should stand on the emerging Cold War between the U.S. and China. When Thatcher stood for the Conservative Party leadership, challenging the incumbent Ted Heath, she declared, “When opportunities come, you should take them.” She did, and the rest is history.

Today, the movement that still idolizes her cannot even decide what the opportunity is, let alone how to take it.

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