This U.S.-led network of international institutions has produced the longest period without a war between great powers since the days of the Roman Empire. We’re at 73 years and counting. Prior to its creation, Europe had plunged the world into two global wars in the span of just 25 years. This alone — peace among the great powers — has been worth every penny spent and every hour of haggling…

In 1945, the U.S. economy had its best year to that point, producing $228 billion in gross domestic product. Adjusted for inflation, that is $3.2 trillion in today’s dollars. The people working round-the-clock in America’s factories and dawn to dusk on its farms, straining to feed, clothe and arm the Allied war effort, might have imagined that no economy could ever run faster. And yet, during the ensuing decades of peace, the GDP of the United States has grown to roughly $20 trillion — more than 500 percent. We’ve accomplished that while also enabling the ruined nations of Europe and Asia, our partners in free trade, to achieve similar economic miracles.

Warts and all, this Pax Americana is the unparalleled gem of diplomatic history and the epitome of bipartisan achievement. President Barack Obama was widely seen as backing away from America’s lead role; now President Trump is reviving the very policies that once darkened the world. I can’t shake the image of that young man. He’s asking: How can you forget?