Opinion | How Kamala Harris Can Really Put America First

If Kamala Harris reaches the Oval Office, she will inherit a dilemma larger than the sum of all the international conflicts and crises that will land on her desk: What is the purpose of American power now?The administration in which Ms.Harris currently serves has not given an adequate answer.

President Biden has armed open-ended wars on the grounds that the United States is still the “indispensable nation” — a grim prospect as an increasingly competitive world imposes escalating costs on a country roiled by troubles at home.The leading global power has lost control of its foreign policy, buffeted from one emergency to the next, unable to set priorities of its own.The present cacophony is decades in the making.

Coming out of the Cold War, successive American administrations chose to pursue global military dominance, even in the absence of rivals.The United States expanded its alliances and stationed troops across the globe, seeking perpetual peace through perpetual strength.

The hope, too, was that the stabilizing effects of U.S.military primacy would spill over into other areas, fostering global cooperation to protect the environment, secure human rights and expand prosperity through trade.But this theory failed — gradually, then suddenly.

Instead of bringing global peace and advantage to Americans, it has embroiled them in a world of conflicts.It hasn’t stopped China from rising or Russia from lashing out, but it has exposed the United States to great risk when they did.

None of this has focused Washington on the threats that touch Americans where they live and work.For eight years, Donald Trump, of all people, has been permitted to monopolize calls for a new vision of America’s role in the world.He has drawn surprising potency from his vow to put “America first,” even as many of his specific policies lack coherence and popularity.

He held the advantage on foreign policy in this year’s election before Mr.Biden stepped aside, and according t...