Former British prime minister Margaret Thatcher died Monday morning of a stroke. She was 87. Thatcher — the U.K.'s first and, so far, only female prime minister — served from 1979 to 1990, restoring and transforming her country's strike-plagued economy. Thatcher, who later was given a life peerage as Baroness Thatcher, led her Conservative Party to three straight election victories (another first), and established herself, alongside her U.S. ally Ronald Reagan, as an architect of the West's victory over the former Soviet Union in the Cold War. Friends and critics alike called her "Iron Lady," for her personal and political toughness. Here, four reflections on what Thatcher meant to her nation and the world:

1. She struck a lasting blow for the free market
When Thatcher took power, says Joseph R. Gregory in The New York Times, Britain "faced disaster. More businesses were failing and more people were out of work than at any time since the Great Depression." Thatcher forced her country to take some "tough economic medicine" — breaking the power of labor unions and making the Labor Party "abandon its commitment to nationalized industry, redefine the role of the welfare state, and accept the importance of the free market." Fighting inflation, budget deficits, and strikes, Thatcher's ratings took wide swings until even her own cabinet ministers revolted in her final year.

But by the time she left office, the principles known as Thatcherism — the belief that economic freedom and individual liberty are interdependent, that personal responsibility and hard work are the only ways to national prosperity, and that the free-market democracies must stand firm against aggression — had won many disciples. Even some of her strongest critics accorded her a grudging respect. [New York Times]

2. But the boldness of Britain's war in the Falklands may define her
"When the strutting head of a military junta General Leopold Galtieri invaded the Falkland Islands, most Britons had to rush to their atlases to find out just where the islands were," says Sky News. Before the 1982 invasion of the islands that Argentines call Las Malvinas, Thatcher was one of the least popular British prime ministers ever. Then, "to the astonishment of people in Britain, to the dismay of the Argentinians, and to the amazement of the Americans and the rest of the world," Thatcher's government sent a task force to the Atlantic off Argentina's coast to reclaim the islands, cementing her reputation as a decisive and powerful leader.

It looked like Lord Palmerston's Gunboat Diplomacy had returned, that Britain was somehow trying to recapture its colonial past, a final hurrah of an Empire on which the sun had set decades before.

The crisis became a defining moment of Margaret Thatcher's premiership, and changed her image and her political fortunes. [Sky News]

3. She helped the West win the Cold War
It was the Soviet press that gave Thatcher her famous nickname, "Iron Lady," says Richard Allen Greene at CNN, after a steely 1976 speech in which she declared that "the Russians are bent on world dominance." Thatcher teamed up with Ronald Reagan, her equally conservative counterpart on the other side of the Atlantic, in a final Cold War showdown with the Soviet Union. She "played a key role in ending the conflict by giving her stamp of approval to Soviet Communist reformer Mikhail Gorbachev shortly before he came to power," saying: "I like Mr. Gorbachev. We can do business together."

That may be the most indelible part of her legacy, says Grant Bosse at the New Hampshire Watchdog. Thatcher, along with Reagan and other allies such as Germany's Helmut Kohl, stood fast against "Soviet expansion at a time when Communism was at its apparent peak."

Margaret Thatcher believed that politicians should stand by their beliefs, and not bend in the name of consensus or popularity. After Churchill, she was the most important Briton of the 20th Century, and one of the key people who secured victory in the Cold War for freedom, democracy, and capitalism. [New Hampshire Watchdog]

4. But in the end, Thatcher remains a deeply polarizing figure
"It's undeniable that for certain generations she is always going to divide the country," historian Timothy Stanley tells USA Today. Some of her critics say her political philosophy was uncaring and inflicted suffering on the poor. "I remember when I was a student, for example, there was a lecturer who at the beginning of the British political history course said: 'Now we all know Margaret Thatcher is evil, but please don't write that on the exam paper,'" Stanley says. "That speaks to how a certain generation in the U.K. feels about her."