We are living in the age of moral panic. We look around, we see a problem, and we rush to outlaw something. Ban TikTok! cry members of Congress. Ban social media for kids! says the state of Florida. Ban immigrants, ban hate speech, ban imports, ban union shops.

Part of what makes a moral panic a moral panic is that fear overwhelms any effort at moderation. Politicians follow the panic. And throughout the nation’s history, an awful lot of moral panics have involved foreigners. Today’s cases in point: The right’s view on immigration and the left’s on Russian election interference.

Back in the 1960s, the economist George Stigler famously wrote that passing a law does not solve a problem. He was arguing against government tendency to impose regulation without sufficient evidence — a process, wrote the future Nobel laureate, that tends to result in rules that are “capricious and arbitrary in high degree.”

In the proposed TikTok ban, we see both aspects of the problem: a lack of evidence and an arbitrary result. But that’s nothing new. Laws resulting from moral panics generally fit that model. And, once adopted, they’re tough to get off the books.

Consider a few examples.

Why are there tight limits to this day on foreign ownership of domestic U.S. air carriers? Blame a moral panic of the past. In the 1920s, Congress voted the first restrictions after General Mason Patrick of the U.S. Army Air Service testified that the nation needed its own civilian aircraft in case they ever had to be called into service. (That was also, said Patrick, the only way to train the pilots we’d need if there was another war.) Later, in the Cold War atmosphere of the 1950s, national security experts issued ominous warnings of the consequences should adversaries have the freedom of American skies. The restrictions were tightened.

Or consider the rules prohibiting issuance of licenses to build nuclear power plants (or perform several other nuclear-related functions) to entities “owned, controlled, or dominated” by foreigners. The source is the same: moral panic. Ironically, the 1946 Atomic Energy Act, passed in the optimistic wake of World War II, placed few limits on foreign investment. The Senate report on the bill conceded that there was no effective way to keep nuclear knowledge from other nations, because the “book of nature” was available to all.

Then came the Cold War. After the Soviet Union successfully tested an atomic bomb in 1949, the U.S. was seized by fear of what the Reds would do next. In 1954, Congress extensively amended the 1946 statute. The new law did more than just ban foreign ownership. A license also could not be granted to any U.S. citizen “deemed to be undesirable from the national security viewpoint.”

The same panic had allowed, in 1950, the passage of a law giving the heads of certain federal departments almost total authority to suspend or fire employees “when deemed necessary in the interest of national security.” In practice, the “deeming” was often by the Federal Bureau of Investigation, which was not required to provide the evidence on which its judgment rested. Moral panic indeed. Of all these laws, only this last has been substantially weakened — the U.S. Supreme Court eventually narrowed the scope of the ability to fire those deemed security risks through an interpretation of the statute.

To be sure, not every moral panic about foreign influence results in lasting legal damage. Consider the temperance movement. As George Fisher of Stanford Law School details in his fascinating new book "Beware Euphoria," the 19th-century temperance movement was deeply nativist, imbued with a sense that non-Protestant immigrants brought with them the corrupting influence of over-indulgence in alcohol. World War I gave the drive for prohibition further impetus, because drinking was seen as so ... well ... German. But of course, the 18th Amendment has been repealed.

The war on drugs, however, is another story. Today, despite widespread fears of Mexican fentanyl, the data show that 89% of traffickers are US citizens. But fears of foreign drugs are longstanding. A single example from Fisher’s book: One argument pressed against opium was the belief that the Chinese had brought it to our shores.

All of which brings us back to TikTok.

According to news reports, we’ve reached the point where legislators who’ll be voting on whether to ban the platform are being opposed by their own children. Young folks love it. But tomorrow they may love something else. Social media may be here to stay, but which platforms are popular is a matter of fashion. They have predictable life cycles. Whether or not the ban passes, within two or three years, a new platform will be the favorite.

That’s another problem with moral panics: The loudest voices are all too often the ones fighting yesterday’s war. But to borrow from Isaac Asimov, anybody can see the crisis once it arrives. The real service to the state is to detect it in embryo.

Stephen L. Carter is a Bloomberg Opinion columnist, a professor of law at Yale University and author of “Invisible: The Story of the Black Woman Lawyer Who Took Down America’s Most Powerful Mobster.”