Many Americans were outraged when President Trump put the United States and Russia on the same moral plane last weekend; he told Bill O’Reilly that Vladimir Putin may be a “killer,” but “there are a lot of killers. You think our country’s so innocent?” Condemnation rippled across op-ed pages and social media. But Trump was just following the logic of the “America first” credo he outlined in his inaugural address and during the campaign: We will not sit in judgment of other nations, because they are doing what it takes to put their own interests first, just as we should. At their core, in relations with one another, all nations are the same.

It is vital to sort out precisely what so many of us are upset about. Trump was not saying anything that left-wing critics of American foreign policy have not been arguing for decades — that before we criticize, sanction and indeed invade other nations, we would do well to remember our own sins: the coups, murders, civilian deaths, destruction and destabilization that we have often wrought in other countries.

More broadly, the basic elements of “America first” have plenty of legitimate historical antecedents, from Hamilton to Jefferson, and should invite a vigorous and even welcome debate. The deeper issue is less about foreign policy than American identity: an assault on the idea and ideals that bind us together as a nation.

Here are the core elements of “America first,” as the president explained them: “We will follow two simple rules: Buy American and hire American. We will seek friendship and goodwill with the nations of the world — but we do so with the understanding that it is the right of all nations to put their own interests first. We do not seek to impose our way of life on anyone, but rather to let it shine as an example. We will shine for everyone to follow.”

Try to separate the message from the messenger and the style from the substance. Put aside the racist historical connotations of “America first,” which are unknown to the vast majority of Americans. Imagine that a leader you support and trust was saying the same thing.

In this light, “buy American and hire American” is an extreme version of an economic nationalist tradition that dates back to Alexander Hamilton, who favored protection of American industries, at least until they could compete on the global stage. The Hamilton Project , a mainstream bipartisan initiative based at the Brookings Institution, rests on the belief both in markets as engines of economic growth and in the use of government power “to enhance and guide market forces.” If those market forces favor the interests of foreign workers over those of American workers, even if American consumers benefit from lower prices, why shouldn’t we put American workers first?

Of course, as economists and business leaders point out, automation has cost far more jobs than offshoring; trade expands the economic pie, and it’s up to us to divide it more fairly; and a beggar-thy-neighbor policy would lead to a global recession, leaving all of us — unemployed Americans most of all — worse off. All true. Still, why not condition any new trade deals on corporate commitments to provide new jobs in the United States, or on tax reform to fund infrastructure projects that would create many American jobs? Take the profits derived from the ability to operate in a global economy and put them to work in the service of national prosperity. Such views at least deserve a hearing and careful thought.

Trump’s insistence that “it is the right of all nations to put their own interests first” is just a blunt restatement of Kissingerian realism: the proposition that in the absence of a world government, all nations seek power to be able to achieve their interests in competition with other nations. Any high-minded moral claims to the contrary are dangerous pretensions.

Realism commands substantial support on both the right (Brent Scowcroft, Richard Haass) and the left (Joe Biden, Les Gelb), for moral and pragmatic reasons. It professes to offer a clear-eyed view of human nature and the workings of power, with the moral case that the pursuit of ideals inevitably ends in tears. The diplomat George F. Kennan, who devised America’s Cold War “containment” strategy, rued the “legalist-moralist” tradition in American foreign policy that led to adventurism in the pursuit of great causes.

The left is quick (and right) to point out the horrific toll in American and foreign lives caused by U.S. efforts to save capitalist governments (Vietnam) or install democratic ones (Iraq), as well as the physical destruction of countries and the destabilization of regions. On the right, Kissinger himself makes the case in his latest book, arguing that “its distinctively idealistic vision of world order” drove the United States into five wars, three of which (Vietnam, Iraq, Afghanistan) it “abandoned . . . midstream as inadequately transformative or misconceived.”

Even for realists, however, the problem is how Trump defines our national interests. He insists, for instance, on getting what we pay for from other nations, immediately and directly. This vision of “America first” demands a reassertion of nationalist freedom of action in the world and a rejection of the multilateral institutions that the United States and its allies have boldly and painstakingly built over the past 60 years. Yet Trump’s predecessors in both parties have believed that upholding the international order that we’ve led (and underwritten) since World War II is itself a national interest, because it provides a measure of peace, stability and prosperity that we would lose if global politics descends once again into a free-for-all. In political science jargon, that order is built on “diffuse reciprocity,” the understanding that if we provide security and an open and stable global economy, our allies and even neutral countries will repay us over time.

As someone who came of age during the Cold War, with memories of World War II fresh in my parents’ and grandparents’ minds, I have long embraced this creed. But many foreign policy experts, including me, have also argued that our international institutions need major reform; that it is impossible to imagine that the world in 2045 will be run by institutions designed for the global power structure of 1945. And President Barack Obama himself pushed hard on our NATO allies to contribute more to our common defense.

Trump’s third proposition, that the United States should not impose “our way of life” but instead serve as an example for others to follow, also has a long pedigree, beginning with George Washington’s advice to steer clear of entangling alliances and Thomas Jefferson’s prediction that the “ball of liberty” would roll around the world without American help. But our founders and our greatest leaders would all be horrified by the example Trump embodies: open contempt for other nations (even allies and their leaders), willingness to bring back torture and “black sites,” a view that winning is the only thing and justifies everything.

At the most fundamental level, Trump would substitute a crude nationalism for the soul of American patriotism. He would have us pledge, as he said in his inaugural address, “total allegiance to the United States of America. And through our loyalty to our country, we will rediscover our loyalty to each other.” That sounds like the tribal nationalism of the Prussians, or the willingness of millions of peasants to die for Mother Russia. The nation is the highest value; its citizens are ultimately expendable for its continuation or its triumph.

America, however, was founded not on national principles but on universal ones. That is the core of the American idea — that all human beings, not just Americans, are created equal. All have natural rights to life, liberty and the pursuit of happiness. We are entitled to those rights not because of our nationality but because of our humanity. Our national experiment is meant to demonstrate what is possible — democratic government, equal protection of the laws, a bill of enumerated rights for all citizens and all persons on our soil — for people everywhere.

Every great American president has embraced this creed. Woodrow Wilson put it best. Speaking to a group of newly naturalized Americans, he said that they had sworn an oath not to any person or set of temporary government officials but “to a great ideal, to a great body of principles, to a great hope of the human race.” Abraham Lincoln similarly described the union as the “last best hope of earth.”

Wilson embodied American history in his combination of grand ideals and personal hypocrisy, striving and falling short. (He was an avowed racist.) We are not better than everyone else. But we publicly announce our intention to hold ourselves to higher standards — not to accept that we are “killers,” just like other nations. Striving to attain those ideals, and holding ourselves to account when we fail, is a central part of what holds us together as a people.

To me, that is what it means to be an American. Not loyalty to a flag, a territory or even to my fellow citizens. But allegiance to something bigger and nobler, that crosses racial, ethnic, religious, gender and cultural lines and gives us a sense of common identity and purpose. We have done terrible things in the world and at home. But we can never simply accept those things or justify them by pointing to the equally bad behavior of other nations. If we do, we trample precisely what is best in us, what has and can again make us great.