For Americans of the Greatest Generation that fought World War II and of the Silent Generation that came of age in the 1950s, the great moral and ideological cause was the Cold War.

It gave purpose and clarity to our politics and foreign policy, and our lives.

From the fall of Berlin in 1945 to the fall of the Berlin Wall in 1989, that Cold War was waged by two generations, and with its end, Americans faced a fundamental question:

If the historic struggle between communism and freedom is over, if the Soviet Empire and Soviet Union no longer exist, if the Russians wish to befriend us and the Maoists have taken the capitalist road, what is our new mission in the world? What do we do now?

The debate was suspended when Saddam Hussein invaded Kuwait. George H.W. Bush assembled a mighty coalition and won a war that required but 100 hours of ground combat.

We had found our mission.

The United States was the last superpower and a triumphant Bush declared that we would build the “New World Order.” Neoconservatives rhapsodized over America's “unipolar moment” and coming “global hegemony.”

But Americans were unpersuaded and uninspired. They rejected the victor of Desert Storm — for Bill Clinton. By Y2K, the Republican Party was backing another Bush who was promising a “more humble” America.

Came then 9/11 and the midlife conversion of George W. to Wilsonian interventionism. After the rout of the Taliban in December 2001, Bush decided to remake Afghanistan in the image of Iowa and to go crusading against an axis of evil. In his second inaugural, he declared that America's mission was to “end tyranny in our world.”

The world declined to oblige. By the end of 2006, the Taliban were back and America seemed in an endless war in Iraq. Republicans had lost Congress, and Bush's democracy crusade was producing electoral victories for Hamas and Hezbollah.

In November 2008, the crusaders were sent packing.

Came then Barack Obama. With the “Arab Spring” beginning in 2010, with dictators being toppled in Tunisia, Egypt, Yemen, Libya and Syria, Obama embraced the movement as his own.

But Obama received a rude awakening. As the Arab dictators began, one by one, to fall, also unleashed and now surging and spreading through the lands they had ruled were the four horsemen of the Arab apocalypse: tribalism, ethno-nationalism, Islamic fundamentalism and anti-Americanism. So we come to an elementary question: If the Islamic world is so suffused with rage and hatred of us — for our wars, occupations, drone attacks, support of Israel, decadent culture and tolerance of insults to Islam and the Prophet — why should we call for free elections, when the people will use those elections to vote into power rulers hostile to the United States?

If the probable or inevitable result of dethroning dictator-allies is to raise to power Islamist enemies, why help dethrone the dictators?

During the Cold War, the United States took its friends where it found them. If they were willing to cast their lot with us, from the Shah to Gen. Augusto Pinochet, we welcomed them. Democratic dissidents like Jawaharlal Nehru in India and Olof Palme in Sweden got the back of our hand. During the Cold War and World War II, the critical question was not whether you came to power through free elections — after all, Adolf Hitler did that — but are you with us or against us?

Ideology, as Russell Kirk admonished us, is political religion, and democracy worship is a form of idolatry, the worshiping of a false god, a golden calf, an idol.

And — while this may border on a hate crime — some countries are unfit for democracy. As Edmund Burke remonstrated: “It is ordained in the eternal constitution of things that men of intemperate minds cannot be free. Their passions forge their fetters.”

With hatred of America rampant across the Arab and Islamic world, we face anew a defining moment. What now is our mission in the world? What now should be the great goal of U.S. foreign policy?

What global objective should we pursue with our trillion-dollar defense, intel and foreign aid budgets, and pervasive diplomatic and military presence on every continent and in most countries of the world? Bush I's New World Order is history, given our strategic decline and the resistance of Russia, China and the Islamic world.

Bush II's democracy crusade and Obama's embrace of the Arab Spring have unleashed and empowered forces less receptive to America's wishes and will than the despots and dictators deposed with our approval.

All three visions proved to be illusions. With America headed for bankruptcy, with new debt of $1 trillion piled up each year, perhaps John Quincy Adams' counsel may commend itself to a country weary from a century of crusades.

“America does not go abroad in search of monsters to destroy. She is the well-wisher to freedom and independence of all. She is the champion and vindicator only of her own.”

Pat Buchanan is a former Republican and Reform Party candidate for President, an adviser to two Presidents, a syndicated columnist based in Washington, D.C., and the author of “Suicide of a Superpower: Will America Survive to 2025?”