It has now been more than a year since Donald Trump, then a candidate for the presidency, said: “My foreign policy will always put the interests of the American people, and American security, above all else. That will be the foundation of every decision that I will make. America First will be the major and overriding theme of my administration.”

Now we know what “America First” means for President Trump: He signed an executive order (now largely vitiated by courts) intended to keep out refugees from nations accused of being hotbeds of terrorism; has vowed to build a massive border wall, though the project has been somewhat de-prioritized; and has promised to institute protectionist trade barriers to stop imports and so improve the lives of American workers, though he has grown shy of his election rhetoric of late.

Trump may have been nudged away from the excesses of his America First plans, but it’s worth asking what the ethical value of his approach was to begin with. Assuming (for the sake of the argument) that Trump’s policies would significantly reduce risks to Americans, isn’t the president justified or even duty-bound, to take strong action to make such risks as low as possible? Or, put differently: To what extent is the president of the United States justified in putting the interests of Americans ahead of the interests of people of other countries?

Answering this question in a way that makes ethical sense requires us not only to consider the benefit to Americans, but the cost to non-Americans.

We can grant that a special responsibility to protect Americans is part of the role of an American president; even so, that responsibility does not give the president a license to disregard the interests of everyone else: The value of a life, after all, is not less because it is the life of a citizen of a different country, nor are the sufferings of families forced out of their homes by persecution or civil war less significant because the families are of a different race or religion. American lives are valuable to Trump first because they are lives, and then especially because they are American; but this line of reasoning only confirms that life itself carries value, and thus Trump cannot ethically pursue a reckless approach to American prosperity.

In the past 70 years, since the end of the Second World War, a more global ethic has become widely accepted among world leaders, and rightly so. It began with the Universal Declaration of Human Rights, and has continued with the acceptance by the United Nations of the doctrine that all countries have a “responsibility to protect” people from genocide and other atrocities. If a government cannot or will not prevent such crimes within its own borders (as happened in the Rwandan genocide, for instance) other countries have a responsibility to intervene, whether or not it is in their own direct interest to do so.

In considering how best to protect Americans, the president should weigh the harm that any policy will inflict on others, wherever and whoever they may be. The executive order on immigration disrupted the lives and careers of hundreds of innocent people, and would have done the same to many more had the courts not halted it. Greater harm has been inflicted on the 60,000 refugees who would have been able to enter the United States during 2017, but now will not be. For them, the harm is likely to be permanent and irreparable, as it is hard to imagine that in future years refugee numbers will be increased to make up for the shortfall this year.

Similarly, the border wall and other rash action on immigration is likely to harm millions, while the benefits for Americans are highly uncertain. His protectionist approach to trade would, if fully implemented, do immense damage. His threat to renegotiate the North American Free Trade Agreement could throw millions of Mexicans out of work and so, ironically, increase the pressure on them to move to the United States. More broadly, reviving protectionism will increase poverty in developing countries just when we were making progress in reducing it.

Of all Trump’s “America First” policies, however, it is his rescinding of the previous administration’s measures to reduce America’s greenhouse gas emissions that is taking the greatest risks, for Americans and non-Americans alike. Perhaps Trump genuinely thinks that climate change is a hoax; but even he must acknowledge that there is a fair chance that he is wrong about that, and the overwhelming majority of scientists are right. In that case, his policies will contribute to heat waves, droughts, crop failures, wildfires and the inundation of coastal cities as sea levels levels rise, both here and abroad. Cheaper energy now doesn’t justify playing Russian roulette with the future of our planet.

In other words, Trump’s America First approach has always been based on a false dichotomy: us vs. them. His proposals threaten the interests of those who are not Americans, without offering genuine benefits for Americans, either.  Not only is Trump’s America First ethic unethical, but it’s also a sham, constructed more for its populist appeal than for anything it will do to improve the lives of Americans.

America is a world leader, and it should be playing a role in making the world a better place for the 7 billion people living in it, and especially for the nearly 1 billion living in extreme poverty. The president of the United States should not follow a policy of always putting the interests of Americans ahead of the interests of everyone else. To give absolute priority to Americans, regardless of the costs to others, is wrong.