Espionage is perhaps as old as war itself. From infiltrating an enemy camp to kill the general, to general intelligence gathering, espionage tactics have largely remained the same throughout most of history. As warfare evolved and entered the modern era, however, so did the tools and techniques of espionage.
Today, spies are equipped with far better and deadlier tools than history. That’s, obviously, the tools and techniques that we know of, as we only know about most of them due to operatives getting caught using them. The best espionage tactics are the ones that have remained hidden throughout history, toppling empires and changing the course of history like few other warfare tactics have been able to.
Of course, that doesn’t mean that we know nothing about spycraft. Thanks to declassified files and information gathered from captured operatives, we’ve come to know of quite a few creative and fascinating espionage tactics that have been used to great success throughout history. Here are our picks for the best of them.
10. False Flag Operations
The term ‘false flag operations’ has its roots in naval warfare, wherein enemy ships would purposefully fly the flag of a friendly nation to trick a fleet into peacefully letting them on-board, and then… well, you know how war works. It has since come to define any espionage operation that seeks to meet a specific strategic objective by putting the blame on someone other than the party carrying it out.
Obviously, that means that we don’t have any legitimate examples of such an operation, as a false flag everyone knows about isn’t technically a ‘false’ flag. Still, many events in recent history have been suspected to be a result of false flag operations carried out by covert operatives. Just take the fire at the Reichstag – the home of the German parliament – in 1933 as one of its most infamous examples. While the event was squarely blamed on a communist called Marinus van de Lubbe and used as an excuse to persecute communist sympathizers in the government, many historians suspect that it was actually the Nazis themselves that had carried it out. Like most other successful false flag operations, though, we may never know.
9. Sun Tzu’s Doomed Spies
One of the primary problems in spycraft is double agents, as no matter how good your spies are, there’s always a scary – even if small – chance that they’ve turned on you and now actually serve the enemy. To counter that, The Art of War – a 5th century BC treatise on warfare written by the famed Chinese strategist Sun Tzu – provides many rather simple and foolproof methods.
One of them was the ‘doomed spy’, which entailed doing certain things just for the benefit of the operatives that may be hiding in your camp. Different from the classic double agent in the way that it didn’t require going through the hassle of seeking out spies and turning them to your side – as you never know how many of them are out there – it sent out the information you wanted the enemy to know with minimal effort.
As Sun Tzu’s techniques are still used in the field to this day provided how effective they’ve proven to be over the centuries, it’s safe to say that many intelligence agencies still deploy this technique to design their military strategies. Though again, if we knew which ones they are, it wouldn’t be a very effective tactic, would it?
8. Non-Human Operatives
It’s hard to think of animals as potential covert operatives, mostly because it’s difficult – almost impossible – to teach them the intricacies of modern geopolitics. However, there have been many officially-unconfirmed reports of countries using animals for spy operations in the past few decades, to the extent that it’d be unfair to completely write it off as a possibility.
Take this recent news of a beluga whale found in Norwegian waters, complete with a tight harness with the words ‘Equipment of St. Petersburg’ imprinted inside, and a mount fit to hold something like a camera or a weapon. While Russian authorities refused to identify it as one of their own, Norwegian researchers were sure that it was one of many Russian animal spies used to gather intelligence in the region.
Then there’s the reports of the US military using a unit of dolphins to guard its fleet during the Vietnam War, as well as sniffing out mines in the Persian gulf in 1987. One ex-Navy veteran who claimed to be a part of a covert dolphin-training program even claimed that some of these dolphins were trained to kill spies with syringes full of carbon dioxide.
7. The Crooked Picture Bomb
It’s a well known fact that during their retreat at the end of WW2, the Nazis were adept at leaving behind clever booby traps to incapacitate allied soldiers looking for weapons or supplies. That included the usual stuff like cartridge boxes or food packets rigged with explosives, though they only targetted the lower-ranked officers. The higher-ups didn’t care much about shiny weapons or food to fall for it, however. For them, the Nazis had the crooked-picture bomb.
Usually placed in abandoned military headquarters, this trap involved purposefully tilting a picture on the wall a bit towards the side. While lower-ranked soldiers rarely bothered with something like that, that wasn’t true for the officers, who were more likely to care about framed art and fix it. When they did, the frame would explode in their face, instantly killing or incapacitating them.
6. Invisible Ink
Invisible ink may sound too obvious to be a successful espionage technique today, though that’s just because of how many times it has been used in spy movies by now. That wasn’t the case during WW1, however, when the concept was still widely unknown.
Recently released documents reveal that invisible ink wasn’t just widely used by spies throughout the war, but that there were many ways to do it. One was soaking a starched handkerchief in nitrate and soda, which could then be soaked in water and turned into invisible ink to write coded messages on the fly. Then there was the classic lemon juice, which worked well enough as invisible ink to be widely used by both sides. The messages could be revealed by just heating the paper, making it a rather effective way of passing coded messages at a time cryptography was still in its infancy.
Ever since the advent of the Internet, email has been an effective potential method of exchanging secret information, as it relies on just the decentralized Internet instead of a particular messaging network that could be monitored and sabotaged. However, as counter espionage tech got better at tracking them, it’s now almost impossible to use emails as an effective method of communication.
While it may seem like an impossible problem to solve, it’s not; just don’t send the mail and save it to drafts. Operatives – especially terrorists – have been caught using this technique to effectively send and receive messages for quite some time now, and according to counter-terrorism experts, it’s quite difficult to counter. It doesn’t leave any digital signature that could be used to track the sender or the receiver of the message. Moreover, the messages in the drafts could be further coded in secret, cryptographically-coded languages.
4. Dead Drop
In traditional espionage, a dead drop refers to a method of passing information which doesn’t require the two parties to ever meet, communicating only through secret locations. It sounds intuitive, but this simple technique has been used throughout history to protect the identities of individual spies, even if ‘dead drop’ was only recently coined by an FBI special agent. We know that it was widely used during the Cold War, as recently-released documents have shown.
While it works the best when it’s used physically, a dead drop could also be implemented digitally for a variety of purposes. As an example, online dark web dealers regularly use it as the preferred method of delivery, using a combination of anonymous browsers like Tor, cryptocurrencies and the old-school technique of ‘trusting a stranger’ to carry it out. Just complete the deal online, physically hide the package at a pre-specified destination – like under a public bus seat – and tell the customer its precise location with photographs. This technique was widely used by a dark web market based out of Moscow, though again, we only know about it because someone was caught. Given how effective it is, dead drops are still presumably widely in use by spies, journalists, online drug dealers and a bunch of other people that require anonymity to operate.
Steganography refers to the umbrella craft of hiding information in a publicly accessible place. While some of the other entries on this list would fall under this category – like invisible ink – they’re only examples of a wide field of study, much like cryptography. Similar to cryptography, steganography has quite a few potential uses in spycraft, as you’d expect.
While the technique has been used to great effect throughout history, the age of computers and the Internet has made it even more relevant, especially for counter terrorism and cyber security. As its most basic example, hackers regularly encode bits of malicious information in the least important parts of a file – which could be anything from a document to a video – to pass through detection software. There were even some reports in 2001 suggesting that Al Qaeda is using the same method to pass information to operatives around the world using pornographic files, though till now, no evidence of it has ever been found.
2. Canary Trap
When you have a lot of suspected spies around you, it becomes difficult to catch all of them. A relatively foolproof technique that has worked against that through the ages has now come to be known as a canary trap. Basically, just give different false pieces of information to each of the suspected spies and see which one gets leaked. The term was first coined by Tom Clancy in his 1987 bestseller Patriot Games, though much like every successful espionage tactic through the ages, it has been used in some form for much longer than that.
It’s not just military espionage either, as canary traps are being increasingly used to improve cyber security in the corporate world, too, where theft of intellectual property is fast coming up as a major problem. One data protection system developed by researchers at Dartmouth College – WE-FORGE – uses AI to create different but still plausibly-similar copies of a document for storage across the network. This could include anything from drug design data to patents, as well as state secrets, spy data, or pretty much anything that could benefit from it. Whenever there’s an attack on the system, the version of the leaked file would reveal precisely where and how it happened, and the cyber-security team would know exactly which vulnerabilities to fix to make the network stronger against similar attacks in the future.
1. Sexual Espionage
While you’d think that using sex for obtaining state secrets is something that only happens in movies, you’d be surprised how widely it’s still used in the real world, and to great success, too. Perhaps one of the oldest methods of espionage, it works exactly how you’d expect. An operative gains access to a high-ranking official by the traditional method of seducing them and gains access to whatever they need. It’s so obvious that it shouldn’t work, though many leaked and declassified reports prove that it still does.
One particularly famous example of the ‘honey trap’ – as the tactic is colloquially called – was Mata Hari, a German spy convicted of seducing French officers and leaking their secrets to Germany during WW1 – even if some historians have expressed doubts about her culpability. Then there’s the case of Marita Lorenz, who was reportedly in a relationship with Fidel Castro and later recruited by the CIA to kill him. She developed cold feet at the last moment, however, thwarting yet another one of the agency’s many attempts against the Cuban premier. These examples are hardly rare, too, as sex has been systematically used for espionage by some of the best intelligence agencies of their times, like the KGB and Mossad.