See if this sounds familiar: a hypothesis is articulated in national security circles that sounds pretty “out there.” When it is first proposed, an avalanche of experts react with easy dismissals. Commentators quote those experts and add their own dismissals. Indeed, the rejections are so swift that they contain elements of mockery.

Time passes, and a funny thing happens. Unexpected voices begin to articulate the renegade idea yet again. The dominant alternative explanations that most experts believed to be true find no evidentiary support. The heretofore crackpot hypothesis no longer seems so crazy. It has not been proven true, mind you — to paraphrase Arthur Conan Doyle, it is simply the best improbable hypothesis remaining after alternatives have been rendered impossible.

Quick, what am I talking about: the claim that UFOs are a real phenomenon or the theory that the novel coronavirus originated in a laboratory accident from the Wuhan Institute of Virology?

The answer is both — but there are some differences between the two narratives that are worth contrasting.

The hard-working staff here at Spoiler Alerts has been making the case for taking UFOs seriously for a few years now. It’s hard not to notice a sea change in elite attitudes on this question. In the past, even policymakers who were intrigued about the question, like John Podesta and Harry Reid, kept their mouth shut.

As my Post colleague Michael Rosenwald reports, the zeitgeist has changed in the past year: “official Washington is swirling with chatter — among top senators, Pentagon insiders, and even former CIA directors — about UFOs. What was once a ticket to the political loony bin has leaped off Hollywood screens and out of science-fiction novels and into the national conversation.”

The willingness of pilots to go on the record about unidentified flying objects, or unidentified aerial phenomena, was one shift. The release of videos in which the pilots sound perfectly sane describing the UFOs they are actually seeing moved the needle further. As these reports went mainstream, the acceptance of their validity by former intelligence chiefs such as James Woolsey, John Brennan and John Ratcliffe have also moved the norm to one of accepting the possibility that something screwy is happening. Now you can write about the subject for the New York Times and it barely raises an eyebrow.

If the mandated unclassified report by DNI on whatever information the government has about UFOs produces anything interesting, that will move the conversation forward further. Perhaps even foreign policy and national security wonks will be able to talk about it openly.

As for the origins of the virus, there had always been a simple macro-story that made sense. As former Clinton national security official Jamie Metzl noted last summer in the Wall Street Journal, “suggesting that an outbreak of a deadly bat coronavirus coincidentally occurred near the only level 4 virology institute in all of China — which happened to be studying the closest known relative of that exact virus — strains credulity.”

Glenn Kessler offers a useful primer on the evolution of this story with lots of useful links. He proffers two reasons for the growing acceptance of the lab theory:

For one, efforts to discover a natural source of the virus have failed. Second, early efforts to spotlight a lab leak often got mixed up with speculation that the virus was deliberately created as a bioweapon. That made it easier for many scientists to dismiss the lab scenario as tin-hat nonsense. But a lack of transparency by China and renewed attention to the activities of the Wuhan lab have led some scientists to say they were too quick to discount a possible link at first.
Sen. Tom Cotton (R-Ark.) from the start pointed to the lab’s location in Wuhan, pressing China for answers, so the history books will reward him if he turns out to be right. The Trump administration also sought to highlight the lab scenario but generally could only point to vague intelligence. The Trump administration’s messaging was often accompanied by anti-Chinese rhetoric that made it easier for skeptics to ignore its claims.

It would be safe to say that proponents of the lab theory are feeling somewhat bitter about the year of calumny they had to tolerate before the hypothesis began gaining wider acceptance.

In both the UFO and the Wuhan lab cases, there remains little direct evidence supporting the claim. What has happened instead is that as more data comes in, the probability of alternative explanations has declined. So it is now respectable to say that these hypotheses need to be considered without sounding like a kook.

The key difference between the two cases of Bayesian updating is the role that partisanship has played. The UFO conversation has been refreshingly devoid of partisan food fights. Once Navy pilots acknowledged that they had seen something strange, politicians on both sides were able to publicly state that further research was needed.

In the case of the Wuhan lab leak hypothesis, partisanship played a huge role in marginalizing the story. The problem with the Trump administration pushing the lab leak hypothesis was that it was coming from an administration that made many, many false claims about the coronavirus pandemic. Its nonexistent credibility on these issues made it harder to believe this argument. The Wall Street Journal’s Jeremy Page, Betsy McKay and Drew Hinshaw explain:

The shift among leading scientists is partly due to conflicting statements from Chinese researchers. Some scientists say another factor has been a toning down of U.S. government rhetoric on the subject in recent months …
President Trump began pushing the lab hypothesis last year, but his administration didn’t make any evidence public.
Other governments that could have helped push for a lab investigation distanced themselves as Mr. Trump began to speak about it, said Andrew Bremberg, the U.S. ambassador to the WHO at the time. “It was like an overnight shift,” he said. “When the president first touched this, they shut down.”

If the lab leak hypothesis winds up being true, Republicans such as Trump, Cotton and Pompeo will crow about how they were proven right. What they will not say is that they needed Joe Biden to be president for the rest of the country to believe in that possibility.