The news that Mike Pompeo, the C.I.A. director, met in secret with North Korea’s leader, Kim Jong-un, over the Easter weekend has renewed hope that one of the world’s most dangerous standoffs might be resolved without war. On Saturday, in fact, Mr. Kim announced that he would halt nuclear tests. Mr. Pompeo’s trip was surprising for many reasons: he went personally, it was kept a secret and it was revealed at a time when others were questioning his fitness to become secretary of state.

But it says something about America’s place in world affairs that at least one aspect of the trip was no surprise at all: that Americans are deeply, centrally involved in a dispute involving two sovereign countries thousands of miles away from Washington.

Of course, there’s a good historical reason. Under American tutelage, South Korea eventually evolved from a desperately poor autocracy to one of the wealthiest democracies on the planet. American taxpayers continue to spend billions of dollars a year to help maintain regional security. A similar process played out in other parts of Asia and in Europe, where the American security umbrella, including tens of thousands of military personnel, provided room for those countries’ leaders to build strong democracies and economies.

American leaders argued that such policies served the cause of global peace and security. They also reasoned that the substantial costs would be tolerable. And, so long as American productivity and workers’ wages were rising, it seemed that Uncle Sam could ensure a decent standard of living at home and security around the world.