WASHINGTON -- The problem with "America First" is that it describes an attitude, not a purpose. It substitutes selfishness for realism.

It implies that nations can go it alone, that we stand for nothing beyond our immediate self-interest, and that we should give little thought to how the rest of humanity thinks or lives. It suggests that if we are strong enough, we can prosper no matter how much chaos, disorder or injustice surrounds us.

America First leads to the diplomacy of narcissism, to use what has become a loaded word in the Trump era. And narcissism is as unhealthy for nations as it is for people.

Perhaps the best approach to the problem as it affects us both individually and collectively was offered by Rabbi Hillel, who lived in the century before the birth of Christ. Hillel's lesson to us began with two questions: "If I am not for myself, who will be for me? If I am only for myself, what am I?"

Precisely. All of us should be prepared to stand up for ourselves. We are patriots because we love our own land in a way we can love no other. But we live in a world of more than 7 billion people and nearly 200 countries. Does our nation not stand for something more than its own existence? Can we possibly survive and prosper if we are only for ourselves?

A constricted view of identity encourages destructive ways of thinking and, paradoxically, actions that reduce the United States' long-term influence. Almost as disturbing as the irresponsibility of President Trump's decision to abdicate American global leadership on the environment by pulling out of the Paris climate accord was the language he used to justify it. He cast the U.S. -- our beloved republic -- as stupid and easily duped, not the shaper of our own fate but the victim of invidious foreign leaders whom he cast as far shrewder than we are.

"The rest of the world applauded when we signed the Paris agreement -- they went wild; they were so happy -- for the simple reason that it put our country, the United States of America, which we all love, at a very, very big economic disadvantage," Trump declared. "A cynic would say the obvious reason for economic competitors and their wish to see us remain in the agreement is so that we continue to suffer this self-inflicted major economic wound."

Really? Our very best friends in the world, starting with Canada, were just trying to scam us? The climate pact was not even a little bit about staving off a catastrophe for the planet we all share? Should we take no pride in helping nudge the environment in a better direction?

And does Trump truly believe that President Obama and the leaders of General Electric, Facebook, Apple, Microsoft, Google, IBM, BP, Disney and Shell are naive idiots? One more question: How could what even Trump had to concede is a "nonbinding" agreement bring about all the horrors he described?

A diplomacy of narcissism is of a piece, to borrow from the historian Richard Hofstadter, with the paranoid style of this president. In his statement, Trump spoke of "foreign lobbyists" who "wish to keep our magnificent country tied up and bound down by this agreement." He painted our nation as a pitiful heap of insecurity. "At what point does America get demeaned?" he asked. "At what point do they start laughing at us as a country?"

If anyone is laughing after Trump's decision, it is our actual enemies and adversaries. They welcome an American leader who wants to rip up or weaken alliances and other forms of collective security that our own practical visionaries, since the days of Harry Truman, Dean Acheson and George Marshall, put in place to advance our purposes.

Tragically, this choice was partly driven by selfish political motives. This only reinforces how narrow a definition of self-interest is in play here. Trump seems to realize how much trouble he is in from the metastasizing Russia story. So he sought to appeal to his political base, shrunken though it is, by re-embracing his "nationalist" side. He said he'd pull out of the Paris agreement and, by God, he did it! Doesn't that make him look strong?

Quite the opposite. The genuinely strong regularly ponder Hillel's second inquiry, "If I am only for myself, what am I?" I don't expect Trump to be troubled by this question, but as a nation, we cannot give up asking it.

(c) 2017, Washington Post Writers Group