The Enemy Within Is Not a Dictator's Belief, It Is His Equipment
Every dictatorship I know of has, at some point, discovered that the nation's troubles were caused by a minority living inside it. The minority changes with the country and the decade: a religion, an ethnicity, a class, a profession, a political tendency, sometimes a group invented for the purpose. The discovery does not change. It arrives on schedule, and it arrives most reliably when the regime is under pressure.
We usually read this as bigotry. The dictator hates the minority, or panders to a population that does. I think that reading gets the causation backwards. The enemy within is not something a dictator believes in. It is a piece of equipment, and it is selected because it does three jobs at once.
Job One: Divide
A population that is united against the regime is the only thing that can remove it. So the first task of any regime that intends to stay is to make sure the population is not united, and the cheapest way to do that is to give the majority someone else to be against.
Blame a minority for the shortages, the crime, the defeat, the decline, and you have converted a vertical conflict, people against rulers, into a horizontal one, people against people. The majority's anger now has a target that is not the palace. Better still, the target lives next door, which makes the anger personal, sustainable, and self-renewing in a way that anger at a distant government never is.
This is the oldest strategy in the manual. Divide and rule was not coined about dictatorships, but dictatorships perfected it.
Job Two: Justify
A regime needs a reason to hold power that its population can be made to accept, and "I enjoy it" is not one. The enemy within supplies the reason.
If there is a dangerous group inside the country, then someone must watch it, and the watching requires a police force with unusual powers. Someone must interrogate its members, and interrogation requires places where the ordinary law does not reach. Someone must prevent it from organising, which requires monitoring everyone's communications, since you cannot know in advance who belongs. Someone must stop it from spreading its ideas, which requires control of the press and the schools.
Every one of those instruments is an instrument of control over the entire population. The minority is the pretext; the population is the object. Once the secret police exists to watch the minority, it watches everyone. Once the emergency law exists to detain the minority, it detains whoever is inconvenient. The apparatus built to protect the majority from the enemy within is the apparatus that will be used against the majority, and it was always going to be, because that was what it was for.
Job Three: Rehearse
The third job is the one least discussed.
A regime that intends to use violence against its own people needs people willing to commit it, and such people are not found ready-made. They have to be produced. The campaign against the minority is where they are produced. It teaches officials that some citizens can be treated as outside the law. It teaches the police that force against civilians is normal. It teaches informers that reporting a neighbour is patriotic. It teaches the population to look away.
By the time the regime turns the same methods on the general population, every part of the machine has already done the work once, on a group whose treatment nobody protested. The campaign against the minority is a dress rehearsal, and like all rehearsals its purpose is the performance.
Why It Escalates to Violence
The strategy has an internal logic that pushes it toward armed conflict, and this too is worth understanding as mechanism rather than as passion.
The enemy within has to remain dangerous, because a minority that has been rendered harmless no longer justifies the apparatus. So the regime must escalate: from suspicion to restriction, from restriction to persecution, from persecution to something the minority eventually resists. When it resists, the regime has its proof. The enemy was violent all along, the apparatus was necessary, and now it needs to be larger. The armed conflict is not a failure of the policy. It is the policy reaching its intended state.
The Diagnostic
None of this means every accusation against every minority is fabricated. Groups do sometimes do harm. But the pattern I have described has a signature, and the signature is checkable.
Ask whether the powers acquired to deal with the minority are scoped to the minority or to everyone. Ask whether the danger is described in terms that could ever be satisfied, or only in terms that require perpetual vigilance. Ask whether the regime became more secure as the minority became weaker, or whether the accusations grew as the regime's other problems did.
When the enemy within grows more dangerous exactly as the regime grows less popular, you are not watching a threat being discovered. You are watching a tool being picked up. The people it will eventually be used on are the ones applauding its use today.