Soon after President Donald Trump’s administration decided to launch a missile strike on a Syrian, critics immediately drew parallels to the Iraq War. We have seen this before, claimed pundits and political commentators. We are getting into another quagmire in the Middle East, just like we did in Libya and Afghanistan. Haven’t we learned our lesson, they asked?

Never mind that foreign intervention has had varied success, the most perplexing facet of the recent debate over Syria is something I call the fallacy of historical resemblance. This fallacy asserts that any two historical moments that share vague similarities should be treated as equivalent, and it comes up all too frequently in historical debate and analysis.

Take the popular new book by Yale professor Timothy Snyder, “On Tyranny: Twenty Lessons from the Twentieth Century.” In it, Snyder, who just this week was appointed as the inaugural Richard C. Levin Professor of History, applies lessons he has learned in studying central Europe to the political climate in the United States today. The text is an expansion of a Facebook post Snyder made in the week following the election, containing a litany of platitudes such as “Stand out,” “Be kind to our language” and “Believe in truth.”

These exhortations are meant to teach Americans how to behave in ways that resist authoritarianism, and they may be very useful for those among us who had planned to cease believing in truth. However, Snyder’s book contains little in the way historical analysis. Rather than argue that the United States is sliding into an era of authoritarian rule, Snyder presupposes it.

“Americans are no wiser than the Europeans who saw democracy yield to fascism, Nazism or communism,” Snyder asserts at the outset. “Our one advantage is that we can learn from their experience.” I can think of a great many advantages we have over Germany in the 1930s, including a robust, growing economy, the strongest military in the world and institutions that have weathered two-and-a-half centuries of political turmoil (The Federal Republic of Germany was only 62 years old when Adolf Hitler rose to power).

Indeed, America’s distinction from interwar Germany can be seen in how the Trump presidency has played out so far. For example, Trump’s two travel bans have both been struck down by the judiciary. His first legislative initiative — the American Health Care Act — did not even make it through a Republican-controlled House of Representatives. If Trump fails to get fellow Republicans to pass his legislation, what indication is there that his administration will soon become the Third Reich?

The apparent source of Snyder’s alarm is that Trump kinda, sorta seems like Hitler. And while it is undeniable that the president exhibits behavior typically associated with strongmen, this hardly indicates that the United States in 2017 is anything like an authoritarian state. What purpose does it serve to draw facile historical connections because of vague similarities between leaders? Likeness and equivalency are dramatically different, and it is irresponsible for historians to group figures and periods because their vague contours seem similar.

To be clear, effective historical inquiry draws parallels between different eras, and academics are correct to apply lessons from history to the present day. However, if we want history to be useful, we have to acknowledge its complexities. Snyder could very well be correct, but the burden of proof likes with him.

In policy debates, both national and at Yale, the fallacy of historical similarity is pervasive. On issues ranging from the student income contribution to college renaming, we are often warned about the risk of being on the “wrong side” of history. Because student movements in the past clamored for much-needed reform, the narrative goes, the administration ought always to give in to student demands. In some cases, of course, this argument is correct. But reductive equivalency only detracts from robust debate.

All nations and institutions are different, and all eras are colored by subtle shades that determine the course of history. The Yale Daily News reported this week that history is once again the most popular major in the college. The job of scholars — especially at a University with a storied history department like Yale’s — is to dissect the nuances of historical eras to promote progress. If we continue to fall into the fallacy of historical similarity, we will never have effective debates on government and history.

Daniel Tenreiro-Braschi is a sophomore in Ezra Stiles College. His column runs on alternate Fridays. Contact him at daniel.tenreiro-braschi@yale.edu .