Nevertheless, she won. In Britain in the Seventies, everything that could be nationalized had been nationalized, into a phalanx of lumpen government monopolies all flying the moth-eaten flag: British Steel, British Coal, British Airways, British Rail . . . The government owned every industry — or, if you prefer, “the British people” owned every industry. And, as a consequence, the unions owned the British people. The top income-tax rate was 83 percent, and on investment income 98 percent. No electorally viable politician now thinks the government should run airlines and car plants and that workers should live their entire lives in government housing. But what seems obvious to all in 2013 was the bipartisan consensus four decades ago, and it required an extraordinary political will for one woman to drag her own party, then the nation, and subsequently much of the rest of the world back from the cliff edge.

Thatcherite denationalization was the first thing Eastern Europe did after throwing off its Communist shackles — although the fact that recovering Soviet client states found such a natural twelve-step program at Westminster testifies to how far gone Britain was. She was the most consequential woman on the world stage since Catherine the Great, and Britain’s most important peacetime prime minister. In 1979, Britain was not at war, but as much as in 1940 faced an existential threat.

Mrs. Thatcher saved her country — and then went on to save a shriveling “free world,” and what was left of its credibility. The Falklands were an itsy bitsy colonial afterthought on the fringe of the map, costly to win and hold, easy to shrug off — as so much had already been shrugged off. After Vietnam, the Shah, Cuban troops in Africa, Communist annexation of real estate from Cambodia to Afghanistan to Grenada, nobody in Moscow or anywhere else expected a Western nation to go to war and wage it to win. Jimmy Carter, a ditherer who belatedly dispatched the helicopters to Iran only to have them crash in the desert and sit by as cocky mullahs poked the corpses of U.S. servicemen on TV, embodied the “leader of the free world” as a smiling eunuch. Why in 1983 should the toothless arthritic British lion prove any more formidable?