When the Berlin Wall fell 30 years ago this month, more than a few experts predicted the end of history: Communism was dead and democracy triumphant.

Now U.S. power would remake the world, which would come to look a lot like America. George H.W. Bush famously called for a “new world order” of “open borders, open trade and . . . open minds,” a new era of international peace and harmony, all to be achieved by American exertion.

But history refused to end. Russia and China conspicuously pursued their own agendas and, in other regions and other places, ancient rivalries flared. None of this stopped American policy makers from pursuing their new global order. All these years later, we are living with the results: the longest war in American history, in Afghanistan; trillions of American dollars expended on failed nation-building; exhaustion at home, aimlessness abroad; and a newly dangerous world.

It’s time for a new departure. The effort to remake the world from Washington has run aground. Now a new strategy abroad must protect American interests and meet American needs by prioritizing the people who sustain America: the middle and working class.

Ours is a middle-class republic, the first of its kind, and we need a foreign policy that protects the prosperity and security of our working people. This is America’s enduring national interest: to preserve, protect and defend our unique way of democracy.

To pursue that interest, America must prevent any one nation from dominating or dictating to us in any key region of the globe. To secure the prosperity of our people and sustain the political and economic independence of our middle class, we need to be free to trade and engage with other nations on free and equal terms.

American foreign policy should be built on preserving our independence and preventing domination by others. That doesn’t mean America needs to be the globe’s policeman or create a world of democracies. Neither of these approaches, sometimes advocated by liberals and sometimes by conservatives, is realistic, and neither is necessary.

We need instead to prevent any other nation from becoming a hegemon?and that brings us to China. While American policy makers have embroiled this nation in multiple Mideast wars, China has steadily built its strength, its economy and its military?all at American expense. For years China has been stealing American jobs and intellectual property, abusing the international trade system. Now it is militarizing the South China Sea and preparing to project its power across the Asia-Pacific region.

China’s expansionist moves are a direct threat to American security. Beijing’s aim is nothing short of domination?first of the region, then of the world. The Asia-Pacific is critical to the prosperity of American farmers, manufacturers and consumers. We can’t afford to be shut out in the years to come, nor can we afford to be reduced to begging Beijing for terms.

China has shown its desire for domination in Hong Kong, where it ruthlessly suppresses its own people and seeks to strip them of their liberties, including the protections of the rule of law. It has betrayed its eagerness to impose authoritarian principles on America in its coercion of the National Basketball Association and other U.S. companies doing business in China. Those are previews of coming attractions if America doesn’t change course.

At this critical juncture, we must abandon the attempt to remake the world and focus on the threat from Beijing. China is not yet so strong that its bid for dominance can’t be resisted. But time is not on our side. Our aim must be to prevent a conflict while securing American prosperity and safety.

We can begin by bringing to a close the “forever wars” in other theaters and redirecting our military’s attention to the Asia-Pacific. There we must forge new alliances and strengthen partnerships to counter China’s threat. We must be prepared to use all the tools at our disposal, including trade and other economic levers, to protect U.S. interests.

In Europe, we must expect our allies to do more for their own defense and to counter a resurgent Russia. And everywhere, in every region, we must ask whether our actions are contributing to the great task of this era, resisting hegemony in the Asia-Pacific.

For most of our history, America didn’t aspire to run the world. We aimed to prevent domination by others, to safeguard our independence, and to make the international order safe for our democratic way of life. These are ambitious aims, and they must again be ours today. The security of our people, and the fate of our republican experiment, depend on it.

Mr. Hawley, a Republican, is a U.S. senator from Missouri.