During his brief inaugural address, President Donald J. Trump called for a new patriotism to “lift our sights and heal our divisions.” In the wake of the most divisive presidential campaign of the modern era, this sentiment was welcome. But the new president also demonstrated why he is an imperfect messenger. Using strident language reminiscent of his combative campaign rhetoric, Mr. Trump described an America characterized by widespread crime and poverty, decaying infrastructure, shuttered factories and failing public schools.

It was a simplistic, almost apocalyptic portrait, one that contains elements of truth but belies the realities of low unemployment, booming markets and falling crime rates. Yet in describing this “American carnage” in the way that he did, Mr. Trump set himself up to point the blame and name his enemy: the political and economic “establishment” that has “protected itself but not the citizens of our country.”

Far from an instrument of healing, the president’s address amounted to a declaration of war on globalization and the elites who reap most of its rewards. Mr. Trump’s first line of attack is old-fashioned nationalism: “It’s going to be America first,” he said, promising “the forgotten men and women of our country” that “every decision” he makes “will benefit American workers and American families.”

This promise echoes the isolationist “America First” rhetoric of the 1930s and 1940s. It is facile and misleading at best. The politics of policy-making, especially in a highly polarized environment, is often a zero-sum game in which some people benefit and some do not. At worst “America First” is a serious threat to the international solidarity that lasting peace and justice require. Our brothers and sisters live not only within our borders but across the world.  

Nationalism is not a new force in American politics. From the start, the national narrative has included an element of American exceptionalism, the belief that the United States has a vital, unique role to play in world history. Yet that mythic hubris takes the form of a false messianism in Mr. Trump’s vision. “At the bedrock of our politics,” he said, “will be a total allegiance to the United States of America, and through our loyalty to our country, we will rediscover our loyalty to each other.”

Patriotic Christians of every political persuasion should see this blind nationalism for the idolatry it is. Students of 20th-century history should see it for the clear danger it is, especially for those whom nationalism inevitably leaves behind. “Greatness for our nation,” Bishop Robert McElroy writes in the upcoming Feb. 6 issue of America, is not an idol, “a possession or power but an ever-challenging aspiration of the heart and soul.”

The ultimate instrument of our unity is the patient grace of God, not the greatness of the nation state. We render unto Caesar what is Caesar’s, but it is in God we trust.

This article appears in February 6 2017.