Of course, a country doesn’t spy only on its neighbors.
We’ve brushed up against this topic before in the context of privacy: the question of who gets to know what about us. Modern technology has made it possible for the government (or corporations) to know a lot, by monitoring our movements with security cameras, subpoenaing access to our emails, placing tracking cookies in our devices, even logging every keystroke we make. Those who favor security over privacy say the innocent have nothing to fear; their opponents disagree.
Some amount of government surveillance is necessary for governing — though the things I’m thinking of would not register on most citizens as surveillance at all. Cadastral surveys, for example, are used to define and map property boundaries, demarcating exactly what land belongs to whom and what resources there the owner has rights over. Medieval Japanese landowners weren’t fond of these because they allowed the government to tax them more effectively, but on the other side of the planet, after the Great Fire of London, precise knowledge of property boundaries was vital for settling disputes between residents after every recognizable marker burned down.
A census is a somewhat more contentious topic. There are actually multiple kinds of census, e.g. of agricultural activity or traffic, but we associate that word primarily with counting people — and often not just counting them, but recording certain kinds of data about them, such as age, ethnicity, religion, wealth, and so forth. And that is indeed information that can be used maliciously: for example, if you know all the people who belong to a minority religion, it makes persecuting them vastly easier. But information also makes it easier to conduct the non-malicious business of government, whether that’s building roads, sending disaster relief, passing protective laws, or bestowing grants.
The mass collection of data is only one facet of the issue, though. Governments also engage in more bespoke, artisanal monitoring of their populaces — and this is where matters transition into the business of espionage.
Spymasters were (and are) every bit as interested in reading the mail of suspected dissidents as that of foreign enemies. The former, however, could be slightly more difficult to arrange: in the days before organized mail services, and without the convenient choke-point of a port or border crossing to help you catch messages coming into the country, you first have to track down the method by which those messages are being conveyed. And when the dissidents in question are illiterate — or just too cautious to commit much to writing — you don’t even have that option.
Instead, you have to spy on them more directly. Word on the street or the testimony of prisoners can lead you to where dissidents tend to gather; then you might lurk in alehouses or at theatres to eavesdrop on their conversations. If they’re smart, they won’t actually air their plans in public, but this can be enough to let you identify some of the players. If lurking doesn’t work, you might instead act like a dissident yourself, noising grievances about loudly enough that the right people might hear and approach you. Then you have your soldiers or police arrest them . . .
. . . or you infiltrate them, the better to uncover and destroy the whole movement. If it’s a well-organized conspiracy, this may take a while; after all, they probably know the government would love to stamp them out. In such cases, the leaders stay well-hidden, and only individuals who have proven their loyalty and trustworthiness are allowed access to those people, or even knowledge of who they are. Reaching that level may be the work of years.
And you might have to do more than just earn their trust. Depending on the group in question, the local laws, and how much the government cares about the latter, do you even have grounds to arrest them? Is the evidence solid enough to stand up in court, and are their crimes serious enough to merit execution, imprisonment, loss of title, exile, or whatever punishment you’re hoping to levy? If not, then you have to do one of two things: be patient, or arrange for the evidence you need.
Yes, this gets very sketchy, very fast. The comparatively thin end of that wedge is the agent provocateur, the person assigned to lure the target into committing a serious enough crime to nail them for. (Actual level of seriousness can vary: in some places and times, just saying “I hope the king dies” is enough, while in others you’d have to actively plot his assassination.) The thick end involves manufacturing and planting evidence of crimes the target didn’t commit. A spymaster might defend these actions by saying a loyal subject could not be lured into sedition or treason, and the person who gets framed is already an enemy of the crown; the frame simply accelerates the process of neutralizing that threat. But from an outside perspective . . . yeah, this work gets profoundly dubious, on both a legal and moral level.
Especially when it expands beyond the sphere of government agents. To me, the most terrifying scenario isn’t the spymaster whose agents could be anywhere; it’s the spymaster who encourages ordinary citizens to inform on one another. Knowing that your own neighbor could report you for untoward activity — or invent untoward activity, if they simply don’t like you — can mean living in a state of constant paranoia. You may wind up policing your own behavior to an obsessive degree, fearing that the smallest move will become your downfall.
Few governments go that far, but quite a few have crossed spies with police to create a “secret police,” a force authorized to maintain internal control by covert means. That term as we use it now is mostly a modern phenomenon, which makes sense; as we discussed before, police in general tilt modern. They tend to require a well-organized bureaucracy, which lots of pre-modern states can’t manage. But there are exceptions: China’s Embroidered Uniform Guard operated for more than two hundred and sixty years, from the late 1300s to the mid-1600s. In other places and times, such agents not be organized into a police-like body, but they could still quietly “vanish” anyone who’s drawn the wrong kind of attention.
The other thing to say about these matters is that they tilt largely urban. Certainly there have been countless peasant revolts in history, but few of them were intensively planned in advance. Many began when some offense happened, someone reacted violently, someone answered the violence with more violence, and soon everyone was taking up arms. The exceptions might well catch the government off guard, because it’s hard to monitor activity in the countryside; travel is slow, people are dispersed, and they’ll notice the presence of strangers far more readily. (Though remember what I said before about merchants operating as spies?) But by that same token, it’s hard for rural people to organize in large numbers and gather the resources necessary to become a significant problem, at least without attracting attention. Many of the biggest threats will originate in urban areas, and so that is where most of the work against them will be concentrated.
To me, internal security falls under the header of “distasteful necessity.” It’s utopian to imagine a government that doesn’t have to worry about any of its citizens plotting political malfeasance; there will always be someone who’s dissatisfied or has their own agenda to push. And a government that decides to prioritize privacy too highly over security won’t last long. But as with anything espionage-related, it’s basically impossible to conduct this work and come out clean — and once you have the capacity to watch for threats, there’s a constant temptation to identify more things as threats, to act sooner and stronger against the ones you see, to claim your ends justify your means.