In a very real way, the 20th century is now over.

The passing of Lady Margaret Thatcher brings the curtain down on an amazing era. In his book “The President, the Pope, and the Prime Minister,” journalist John O’Sullivan told the story of how Lady Thatcher teamed up with then-President Reagan and Pope John Paul II to confront the Soviet empire when it was at its peak and seemed invincible. Her strong leadership was a key reason the West won the Cold War “without firing a shot,” to use her own words.

Lady Thatcher now takes her place in history alongside Sir Winston Churchill, the Duke of Wellington and all the other great British heroes who defeated enemies of their island nation. She was an intrepid warrior for freedom and human dignity, and understood that the way to defeat communism wasn’t to appease it, but to confront it and highlight its weaknesses.

But she was far more than just the “Iron Lady,” a nickname bestowed on her begrudgingly by a respectful Soviet adversary. She also faced, and dispatched, challenges on the home front.

We might not remember how desperate Britain’s situation was in the late 1970s, when the country was described as the “sick man of Europe.” To pay its bills, Britain had to borrow from the International Monetary Fund. Protracted labor disputes led to long strikes and what was called a “winter of discontent.”

Strikes frequently brought the country to a halt; dead bodies went unburied, and uncollected trash piled up in the streets. But they also brought Lady Thatcher to power.

In 1979, the Labor prime minister lost a vote of no confidence, and the Conservative Thatcher organized a new government. She was convinced that the solution to Britain’s problems lay in a return to the free-market system. So she set out to end the “nanny state” and break the grip of power-hungry trade unions and the monopoly of nationalized industries.

Lady Thatcher’s approach to the coal miners highlights her success. A previous miners’ strike had brought down a Conservative government. But she stood firm in the face of a violent strike in 1984 and refused to cave in to radical demands. Soon, her privatization program saw the government sell off British Telecom, British Gas, British Airways and British Steel.

Customers saw better service, and average British citizens became stockholders and investors instead of, essentially, employees of the state. With these advances, Britain enjoyed an historic boom. It boasted the highest rate of growth in Europe, and household incomes jumped 34 percent. Renters became homeowners, and a growing economy created more jobs.

Meanwhile, Lady Thatcher was doing what would have seemed impossible before her tenure: she reduced government spending, slashed the budget deficit, cut taxes and eased regulations. She knew that freedom works, and her reforms proved it beyond a doubt. Small wonder that, when they finally achieved their independence from the Soviet Union, most countries in the newly free Eastern Europe adopted Thatcher-style reforms to boost their economies.

Lady Thatcher’s legacy echoed around the world, because she recognized the importance of forging strong alliances.

She first met Ronald Reagan in 1975, when she was Britain’s Conservative Party leader and he a former California governor. They realized they shared the same philosophy and could work together to put that philosophy into place.

Reagan later recalled, “Margaret ended our first meeting by telling me, ‘We must stand together.’ ” And they did so, as staunch friends, political soul mates and champions of liberty.

That close personal relationship — even stronger than that enjoyed by Franklin Roosevelt and Churchill during World War II — helped to strengthen the strategic relationship between our two countries and form the foundation upon which “the West’s” the military and economic power rests. Reagan was able to obtain international support for U.S. initiatives because of Lady Thatcher’s help, and the United States stood behind our ally during the Falklands crisis.

At Reagan’s state funeral, Lady Thatcher gave the eulogy. After describing the many historic tasks the late president had successfully undertaken, she concluded: “Let us give thanks today for a life that achieved so much for all of God’s children.” 

Those words apply equally well to Lady Thatcher’s own life. She belongs to the ages now. The rest of us owe her a debt we can never truly repay. But we will do our best to live up to her example of principled leadership and iron will.

-Feulner is the founder of The Heritage Foundation, home of the Margaret Thatcher Center for Freedom.