LONDON -- There is a story, probably apocryphal, about Margaret Thatcher who became prime minister 30 years ago this week and led Britain's economic and political revival.

The newly elected Thatcher takes her all-male cabinet to dinner. The waiter asks her what she would like to order.

"I'll have the beef," says she.

"What about the vegetables?" asks the waiter.

"They'll have the same."

The story says much about a woman who in many ways exuded more gravitas than most of her male contemporaries, which is why, in 1990, they conspired to dump her as leader of the Conservative Party.

Not since Winston Churchill -- and not since Thatcher -- has Britain had such a dominant leader; even Tony Blair could not measure up to the Iron Lady.

To gauge her success, one must recall Britain's condition before she took office. Like Jimmy Carter's America in 1979, people were talking about managing Britain's decline. As Robin Harris writes for The Heritage Foundation, "The pace and scale of this revolution justifies the description, even though the chief revolutionary herself was someone of very traditional instincts who always considered that she was restoring what had been lost, not imposing a utopian plan."

This is the definition of "conservatism." Thatcher understood proven principles. She wasn't looking for "new" things, but rather old things that had proven to be successful. She called on the British people to remember their history and to embrace it. She was not indulging in nostalgia so much as she was taking from a living past in order to build a better future. In this, she was the mirror image of Ronald Reagan.

This is the key to leadership. Leadership doesn't lie in poll numbers, though all politicians take polls to measure the public temperature. Leadership is about convictions with ample references to past successes and the principles behind them. If one doesn't bake a cake without first reading the directions, how can a damaged nation be repaired without discerning what works and what doesn't? If a people forget their history -- as too many in Britain and America have done -- they are then susceptible to being snookered by politicians who propose something "new."

Given our self-centeredness, it is refreshing to recall what Lady Thatcher said about personal accountability and responsibility: "Disciplining yourself to do what you know is right and important, although difficult, is the high road to pride, self-esteem and personal satisfaction."

First, one must know what is "right." In our "anything goes" culture we are told that people who believe they have discovered "right" are wrong, because that requires judgment and someone's feelings might be hurt if they hold to another "tradition."

As for the notion of "fairness" and "spreading the wealth around," which is the philosophy of the Obama administration, Lady Thatcher said, "I do not know anyone who has got to the top without hard work. That is the recipe. It will not always get you to the top, but should get you pretty near." Today, in America and increasingly in Britain where Chancellor of the Exchequer Alistair Darling has proposed a 50 percent tax on "the wealthy," admitting he just plucked the figure "out of the air," hard work is to be punished and slothfulness subsidized.

About wealth, Lady Thatcher said: "It's not the creation of wealth that is wrong, but the love of money for its own sake." Republicans in America, now debating among themselves whether to appeal to "moderates" to rebuild their party, would do well to consider Thatcher's wisdom: "Standing in the middle of the road is very dangerous; you get knocked down by the traffic from both sides."

Britain, like America, is not in turmoil because it once embraced the conservative principles of Margaret Thatcher -- principles that worked. Britain and America are in turmoil because they too quickly abandoned Thatcher's principles in favor of a superficial, "feel-good" philosophy. Using another food analogy, we want dessert before -- even instead of -- our vegetables, though we know what's best for us.

Lady Thatcher's official portrait will be unveiled this week and hung at 10 Downing Street. A greater honor would be for the British people to again "hang" her principles in their minds and hearts. It is something the Conservative Party leader David Cameron has pledged to do should he prevail in next year's scheduled elections.