Friday 6 November 2026
What Does a Threat Threaten?
More than 30 European flights received bomb threats this week. Every one investigated so far has been a false alarm. The disruption, however, has been entirely real.
The Guardian reported yesterday that at least 25 flights across Europe were disrupted by bomb threats on Thursday alone: aircraft diverted, airports evacuated, fighter jets scrambled.1 2 Emails sent to airports in Rome and Sofia were signed »fighters of the Male State« – a Russian far-right, misogynist movement with no established connection to the threats. No explosives have been found on any aircraft. The obvious questions are who is behind this, why they do it, and whether there are actual bombs. But there’s another, more fundamental one: what does a threat actually threaten?
»Planes are designed to be extraordinarily safe, but not perfectly safe. The accepted risk of a catastrophic failure is already vanishingly small: no more than one in a billion flight hours. So why does a threat change everything?«
The philosopher Terrence Deacon uses the term »absential causation«3 for how something that isn’t there can still produce real effects – a hole in a fence determines where an animal escapes, though the hole itself does nothing. A bomb threat works the same way: the bomb doesn’t have to exist. The possibility of there being one is enough to divert an aircraft, mobilise security services, and disrupt an entire transport network. The threat produces its own reality.
But there’s something more peculiar about this particular kind of threat.
Someone planning to bomb a plane has little reason to announce it first: a warning gives security services time to find the device. Neither the Lockerbie bombing nor the destruction of Air India Flight 182, the two deadliest attacks on passenger aircraft, was preceded by a specific, actionable warning. A hoaxer, by contrast, can issue a threat for almost nothing; the warning is the entire operation.
This changes how we should read the signal. Normally, we treat a warning as evidence of danger, even once it turns out to be false. But when genuine attackers have little incentive to warn and hoaxers have every incentive to, the signal starts pointing the other way. A threat is in fact evidence against the thing it threatens.
That doesn’t mean a threat should necessarily be ignored. The consequences of missing a real bomb are catastrophic, investigating a false alarm is comparatively cheap, and so even a very low probability can justify grounding an aircraft or evacuating an airport. But aviation doesn’t operate on zero risk. Planes are designed to be extraordinarily safe, but not perfectly safe. The accepted risk of a catastrophic failure is already vanishingly small: no more than one in a billion flight hours.4 So why does a threat change everything?
Part of the answer is credibility. Economist Thomas Schelling argued that a threat is more convincing when it’s costly to make, because that makes it harder to fake.5 Specific details have traditionally helped establish that credibility. But, as The Guardian points out, information that once required insider access, such as flight numbers, routes, and aircraft types, is now freely available online. What looks like privileged knowledge costs almost nothing to produce.
The familiar film scene in which a captor must provide a photograph of the hostage holding today’s newspaper illustrates the principle: demand something that is costly to fake. (Note to filmmakers: AI has made it easier to fake that image.) Aviation security could apply the same logic, asking for a verifiable detail about the bomb’s location or placement that only someone who had actually planted it would know. Without that, the threat is just a claim.
This is a Bayesian problem in miniature: what should move the odds isn’t how a threat reads, but how often real bombers versus hoaxers produce one at all. The photograph-with-a-newspaper trick is the same move made practical: demand evidence that shifts those odds, not evidence that merely sounds specific.
Psychologist Baruch Fischhoff showed in 1975 that, once we know how something ended, we tend to think it was predictable all along.6 An official who ignored a warning before a disaster looks negligent; one who faced the same disaster without a warning looks unlucky. So there’s another calculation at work, almost separate from the actual risk of a bomb: not the odds of an explosion, but the odds of being blamed for having done nothing. The system is less concerned with whether a bomb is likely than with whether its response can be defended.
A threat doesn’t make a plane more dangerous than any other. But it gives the authorities something they can’t afford to ignore. The response may be as much about protecting themselves as protecting the passengers: if something terrible happens, nobody can ask why they did nothing. The bomb may be imaginary. The liability is not.
References
1 Jakub Krupa (2026) »Why have more than 30 European flights been hit by bomb threats this week?«. The Guardian, 5 November.
2 Rory Carroll, Gwyn Topham, Jakub Krupa & Dan Sabbagh (2026) »Bomb threats disrupt at least 25 flights across Europe, raising hybrid war fears«. The Guardian, 5 November.
3 Terrence W. Deacon (2011) Incomplete Nature: How Mind Emerged from Matter. W.W. Norton.
4 Federal Aviation Administration (2024) Advisory Circular 25.1309-1B: System Design and Analysis – defines “extremely improbable,” the standard for a catastrophic failure condition, as a probability of 1×10−9 or less per flight hour. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_25.1309-1B.pdf
5 Thomas C. Schelling (1960) The Strategy of Conflict. Harvard University Press.
6 Baruch Fischhoff (1975) »Hindsight is not equal to foresight: The effect of outcome knowledge on judgment under uncertainty«. Journal of Experimental Psychology: Human Perception and Performance, 1(3), pp. 288–299.