The U.S. bombing of Syria puts on the front burner the question of whether or not Donald Trump will actually be as much of a radical departure from the internationalism of his predecessors as “America First” would imply. I don’t think Syria answers the question, because (beyond the obvious and appropriate outrage at President Assad’s use of chemical weapons on his own people) there is ample domestic logic for Trump’s move. Barack Obama prevaricated for years on Syria; Trump acted decisively. The fact that Russia supports Syria also played into the decision, if Trump is worried about perceptions that he is too close to Vladimir Putin.

But the broader question of “whither American internationalism?” remains very much on the table. The question is not only important. It also has very deep roots—in American history, in the national psyche, and in U.S. elections. Let me begin with history.

For several years after the 9/11 attacks, I taught a class called “U.S. in the World.” I would always start the class the same way, by asking students the same pair of two-part questions:

When did World War I start? When did the U.S. enter the war?

When did World War II start? When did the U.S. enter the war?

Many students could only answer the final question. Everyone in America knows the answer: “Pearl Harbor,” even if the precise date couldn’t be recalled.

More importantly, everyone in America knows what happened after Pearl Harbor. The U.S. saved the world from fascism. America then presided over the rebuilding of Europe and Japan and made them allies. The U.S. built the international system of the United Nations, the International Monetary Fund and World Bank, the forerunners to the World Trade Organization. America became the global police. In the words of former Secretary of State Madeleine Albright in 1998, the U.S. was the “indispensable nation”—the only country capable of, and interested in, policing an international system; a system from which it benefited immensely.

“America First” makes Donald Trump the first president since Franklin Delano Roosevelt to seriously consider making the U.S. more insular than indispensable. I think that would be a massive mistake, for America and for the world.

But before I make that case, I want to link America’s pre-WWII history to the political sentiments behind “America First.”

There were almost five years of world war in the 20th century in which the U.S. was not involved—from September 3, 1939 to Pearl Harbor and from August 4, 1914, when Great Britain declared war on Germany and the U.S. declared its neutrality, to April 6, 1917, when the U.S. declared war on Germany amid concerns it would invade Mexico (32 months).

Woodrow Wilson was an inveterate internationalist who had the power of a second term after his reelection as president in 1916. But he could only get the U.S. into World War I after the consensus view became that Germany had its eyes on Mexico.

Roosevelt was also an internationalist whose political capital was immense after beating the Great Depression. But even after being re-elected as president twice (1936 and 1940), and after working hard to support Britain and the Allies short of declaring war, he could only lead the U.S. into WWII when Pearl Harbor was bombed.

In fact, I would argue that, before Pearl Harbor, the central tendency for America was to be insular—economically protectionist, wary of foreign entanglements, and with a relatively narrow view of American national interests.

That seems unthinkable today, or at least unthinkable based on the arc of history following Pearl Harbor.

But now President Trump is making it thinkable. He wants to impose punitive tariffs on countries like China and Mexico. He wants allies like Germany and Japan to pay for their own defense. He wants to ignore Russian territorial expansionism. He wants to build up the U.S. military, but only to use it to defeat ISIS.

The opinion polls show that lots of Americans agree with him. They believe globalization hurts more than it helps. They view the post-9/11 wars as futile wastes of lots of money. They consider international organizations irrelevant indulgences and diversions.

In this sense, “America First” is back to the future for the U.S.—more insular than international. But I don’t want to get into an argument about the essence of America’s approach to the world. Far from it.

“Now is the time for leadership, to explain why an America that is fully engaged in the world is in the country’s interest. Hillary Clinton tried and failed. Donald Trump won in part for taking the opposite side.”

If the U.S. had not entered World War II, who knows what would have happened, to the world, and ultimately to America? If the U.S. turns its back on the world and builds barriers, I know it will not only be bad for the world. It would be bad for America too.

The simple reason is that, even in the 1930s, the U.S. was a country distant—psychologically, geographically, economically—and at arm’s length from the world. That is a far cry from today, where the U.S. is at the epicenter of everything.

America is the global magnet for talented and ambitious people from all over the world. American technologies and American companies dominate global commerce. The U.S. spends almost as much on the military as the rest of the world combined.

Yes, China is rising. Yes, terrorism seems capable of undermining even the strongest defense. Yes, for far too many Americans, standards of living have been stagnant for far too long.

But I believe all this makes the U.S. more essential than it was 20 years ago. And I also believe the costs to Americans of insularity—from giving China and Russia freer rein in global affairs to increasing the price of all the imports Americans consume—are higher too.

Now is the time for leadership, to explain why an America that is fully engaged in the world is in the country’s interest. Hillary Clinton tried and failed. Donald Trump won in part for taking the opposite side.

When it comes to the Trump administration, however, it is essential to separate the symbols from the substance. And there is more of the former than the latter.

What happens next in Syria remains to be seen. But American boots on the ground in some type of Iraq 2.0 seems to be the most unlikely outcome. On other fronts, the early returns suggest a retreat from “America First” and a reversion to the mean, at least where policy and substance are concerned.

The immigration ban will likely remain hung up in the courts. There will be a wall with Mexico (there already is a partial one) but it will be a way to regulate commerce as much as anything else. The U.S. has not officially triggered the process of naming China a currency manipulator, the precursor to imposing tariffs. “Border adjustment” taxes are so complex that few people think they will ever be levied.

No one should expect Trump to embrace internationalism. But notwithstanding all the symbolism of “America First,” don’t expect him to implement insularity. Because the U.S. is in a fundamentally different and better place in the world than it was before Pearl Harbor.


Editor’s Note: This post was originally published on Dean Geoffrey Garrett’s LinkedIn page, where he was named an “influencer” for his insights in the business world. Geoffrey Garrett is Dean, Reliance Professor of Management and Private Enterprise, and Professor of Management at the Wharton School of the University of Pennsylvania. Follow Geoff on Twitter. View the original post here.