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?