Washington ? One measure of a leader’s greatness is this: By the time he dies, the dangers that summoned him to greatness have been so thoroughly defeated — in no small measure by what he did — it is difficult to recall the magnitude of those dangers, or of his achievements. So if you seek Ronald Reagan’s monument, look around, and consider what you do not see.

The Iron Curtain that scarred a continent is gone, as is the Evil Empire responsible for it. The feeling of foreboding — the sense of shrunken possibilities — that afflicted Americans 20 years ago has been banished by a new birth of the American belief in perpetually expanding horizons.

In the uninterrupted flatness of the Midwest, where Reagan matured, the horizon beckons to those who would be travelers. He traveled far, had a grand time all the way, and his cheerfulness was contagious. It was said of Dwight Eisenhower — another much-loved son of the prairie — that his smile was his philosophy. That was true of Reagan, in this sense: He understood that when Americans have a happy stance toward life, confidence flows and good things happen. They raise families, crops, living standards and cultural values; they settle the land, make deserts bloom, destroy tyrannies.

Reagan was the last president for whom the Depression — the years when America stopped working — was a formative experience. Remarkably, the 1930s formed in him a talent for happiness. It was urgently needed in the 1980s, when the pessimism of the intelligentsia was infecting people with the idea that America had passed its apogee and was ungovernable.

It also was said then that the presidency destroyed its occupants. But Reagan got to the office, looked around, said, “This is fun. Let’s saddle up and go for a ride.” Which he did, sometimes in the middle of the afternoon. Scolds, who thought presidents were only serious when miserable, were scandalized.

In an amazingly fecund 27-month period, Margaret Thatcher, Pope John Paul II and Reagan came to office. The pope and the president had been actors. Reagan said he wondered how presidents who have not been actors could function. Certainly the last century’s greatest democratic leaders — Churchill, FDR — mastered the theatrical dimension of politics.

Good actors, including political actors, do not deal in unrealities. Rather, they create realities that matter — perceptions, aspirations, allegiances. Reagan in his presidential role made vivid the values, particularly hopefulness and friendliness, that give cohesion and dynamism to this continental nation.

A democratic leader’s voice should linger in his nation’s memory, an echo of his exhortations. Reagan’s mellifluous rhetoric lingers like a melody that evokes fond memories. Because of demagogues, rhetoric has a tainted reputation in our time. However, Reagan understood that rhetoric is central to democratic governance. It can fuse passion and persuasion, moving free people to freely choose what is noble.

He understood the axiom that people, especially Americans, with their Founders’ creed and vast reservoirs of decency, more often need to be reminded than informed. And he understood the economy of leadership — the need to husband the perishable claim a leader has on the attention of this big, boisterous country.

To some, Reagan seemed the least complicated of men — an open book that the country had completely read. However, he had the cunning to know the advantage of being underestimated. He was more inward than he seemed. And much tougher. The stricken fields of American and world politics are littered with those who did not anticipate the steel behind his smile.

The oldest person ever elected president had a sure sense of modernity, as when he told students at Moscow University that mankind is emerging from the economy of muscle and entering the economy of mind. “The key,” he said, “is freedom,” but freedom grounded in institutions such as courts and political parties. Otherwise “freedom will always be looking over its shoulder. A bird on a tether, no matter how long the rope, can always be pulled back.”

Reagan was a friendly man with one close friend. He married her. He had one other great love, for the American people, a love intense, public and reciprocated.

Presidents usually enter the White House as shiny and freshly minted dimes and leave tarnished. Reagan left on the crest of a wave of affection that intensified in response to the gallantry with which he met illness in his final years.

Today Americans gratefully recall that at a turbulent moment in their national epic, Reagan became the great reassurer, the steadying captain of our clipper ship. He calmed the passengers — and the sea.

George Will is a columnist for Washington Post Writers Group.