A Vietnam vet friend of mine argues that maintaining a democracy requires three things: a passion for freedom, tolerance for diversity and intolerance for threats.

A letter from a reader, responding to a column on Iraq's struggling democracy, suggested I write about the United States' own tortuous path -- sketching a nation that began with limited voting rights and confronted powerful factions, ethnic animosities, urban riot, rural rebellion and destructive civil war. The reader thought America's saga might help the public "understand that this democracy thing is hard."

Hard indeed. Mull my friend's threefold guidance, and you'll find tricky paradox after paradox entwined within several enigmas. Balancing tolerance and intolerance is an obvious tension, which requires reason, experience, maturity and discipline, but the aspiration for freedom, the drive to obtain it and retain it, also involves emotional passion and desire.

America itself is a structural paradox. The United States is a republic -- for good reason. America's founders saw dangers in what James Madison (Federalist Paper 10) called "pure democracy ... a society consisting of a small number of citizens, who assemble and administer the government in person." Madison argued this arrangement had "no cure for the mischiefs of faction," and weaker parties and "an obnoxious individual" were vulnerable to "pure" majority rule.

Yet a muscular democratic spirit empowers the Constitution's opening phrase, "We the people of the United States." America is a balancing act, where democratic practices and values steer the republic.

Democracy and freedom, that passionate objective, are closely linked, but democracy in practice is an exercise in restrained freedom. Liberty without responsibility quickly and all too easily degrades to libertinism, which is why maintaining democracy demands shared responsibility.

But shared responsibility -- what a risky demand. Human beings may behave nobly and sacrificially; they also behave abysmally and selfishly. During the Cold War, Jean Francois Revel wrote in "How Democracies Perish" that "democracy may, after all, turn out to have been a historical accident. ... Democracy is by its very nature turned inward. Its vocation is the patient and realistic improvement of life in a community."

Revel echoed John Adams' observation of 1814: "Democracy never lasts long. It soon wastes, exhausts and murders itself. There was never a democracy yet that did not commit suicide."

Revel saw democratic practice as paradox fraught with social reward and danger. "Societies of which permanent criticism is an integral feature are the only livable ones," he wrote, "but they are also the most fragile." Continued...