Restore the three sinews of American influence: our economic strength, our military strength and the strength of our values.

Disturbing developments are sweeping across the greater Middle East. In Syria, tens of thousands of innocent people have been slaughtered. In Egypt, the Muslim Brotherhood has come to power, and the country's peacetreaty with Israel hangs in the balance. In Libya, our ambassador was murdered in a terrorist attack. U.S. embassies throughout the region have been stormed in violent protests. And in Iran, the ayatollahs continue to move full tilt toward nuclear-weapons capability, all the while promising to annihilate Israel.

These developments are not, as President Obama says, mere "bumps in the road." They are major issues that put our security at risk.

Yet amid this upheaval, our country seems to be at the mercy of events rather than shaping them. We're not moving them in a direction that protects our people or our allies.

And that's dangerous. If the Middle East descends into chaos, if Iran moves toward nuclear breakout, or if Israel's security is compromised, America could be pulled into the maelstrom.

We still have time to address these threats, but it will require a new strategy toward the Middle East.

The first step is to understand how we got here. Since World War II, America has been the leader of the Free World. We're unique in having earned that role not through conquest but through promoting human rights, free markets and the rule of law. We ally ourselves with like-minded countries, expand prosperity through trade and keep the peace by maintaining a military second to none.

But in recent years, President Obama has allowed our leadership to atrophy. Our economy is stuck in a "recovery" that barely deserves the name. Our national debt has risen to record levels. Our military, tested by a decade of war, is facing devastating cuts thanks to the budgetary games played by the White House. Finally, our values have been misapplied—and misunderstood—by a president who thinks that weakness will win favor with our adversaries.

By failing to maintain the elements of our influence and by stepping away from our allies, President Obama has heightened the prospect of conflict and instability. He does not understand that an American policy that lacks resolve can provoke aggression and encourage disorder.

The Middle East is a case in point. The Arab Spring presented an opportunity to help move millions of people from oppression to freedom. But it also presented grave risks. We needed a strategy for success, but the president offered none. And now he seeks to downplay the significance of the calamities of the past few weeks.

The same incomprehension afflicts the president's policy toward Israel. The president began his term with the explicit policy of creating "daylight" between our two countries. He recently downgraded Israel from being our "closest ally" in the Middle East to being only "one of our closest allies." It's a diplomatic message that will be received clearly by Israel and its adversaries alike. He dismissed Israel's concerns about Iran as mere "noise" that he prefers to "block out." And at a time when Israel needs America to stand with it, he declined to meet with Prime Minister Benjamin Netanyahu.

In this period of uncertainty, we need to apply a coherent strategy of supporting our partners in the Middle East—that is, both governments and individuals who share our values.

This means restoring our credibility with Iran. When we say an Iranian nuclear-weapons capability—and the regional instability that comes with it—is unacceptable, the ayatollahs must be made to believe us.

It means placing no daylight between the United States and Israel. And it means using the full spectrum of our soft power to encourage liberty and opportunity for those who have for too long known only corruption and oppression. The dignity of work and the ability to steer the course of their lives are the best alternatives to extremism.

But this Middle East policy will be undermined unless we restore the three sinews of our influence: our economic strength, our military strength and the strength of our values. That will require a very different set of policies from those President Obama is pursuing.

The 20th century became an American Century because we were steadfast in defense of freedom. We made the painful sacrifices necessary to defeat totalitarianism in all of its guises. To defend ourselves and our allies, we paid the price in treasure and in soldiers who never came home.

Our challenges are different now, but if the 21st century is to be another American Century, we need leaders who understand that keeping the peace requires American strength in all of its dimensions.

Mr. Romney is the Republican Party candidate for president.