Perimeter Security Pt 1

Posted: October 18, 2013 in A Combative Insight, Perimeter Security Pt 1

Perimeter Security
By Bo Perrin

Perimeter security is the heart of home combatives. Every insurgent must cross some territory to gain access points into the house. The fact is many people begin perimeter house and backyardsecurity at the front door. Actually, perimeter security needs to be pushed back as far away from the structure as is possible.

I was a law enforcement specialist in the pre-Obama USAF. I held a number of specialities within my AFSC. One speciality in which I was trained was a combat specialist. A significant difference exists between USAF combat training and the combat training a Marine or soldier goes through. Generally, speaking the Marines and Army train to combat other military entities on open fields similar to the fields of France and Germany in World War 2. Some of this has changed. In Vietnam both the Army and Marines set up fire bases that they would use as the focal point of their operations in that area. In this case, both the Marines and Army would set up a perimeter security generally in a circular fashion. The same is true for many bases in Iraq and Afghanistan.

Nevertheless, those Security personal who were chosen to receive USAF combat training, trained specifically to protect a base. Base security had two forms. One form was similar to what I did at Ramstein Air Base. Here, the base was in friendly territory, i.e., Germany. Our ramsteinsecurity was limited to the base perimeter unless an emergency demanded that we purse someone off-base. Otherwise, the territory outside the perimeter was under the jurisdiction of the German Polizei. The other form is similar to air bases set up in territory in which we are engaged in hostilities like Vietnam, Iraq or Afghanistan. Here, protocol demanded that our security perimeter extend as far as is needed to protect the base.

Interestingly, no matter what protocol limited or permitted the base security perimeter was a series of three concentric circles. The outer perimeter, the 3rd circle, was either the physical base perimeter which is generally a fence or the base perimeter set up by military authorities when in hostile environment. The next perimeter, the 2nd circle, is arbitrarily created and placed usually dividing nonmilitary from military base sources. In such cases, this circle would separate base housing from the JAG office. The final perimeter, the 1st circle, was drawn around headquarters. Headquarters is viewed as the brain of all military operations and therefore, it is to be defended at all costs.

This purpose of the 3rd perimeter was primarily early warning. Security personnel set up various early warning systems like flares, claymores etc., to warn of enemy movement. Generally, security forces did not heavily defend this line nevertheless, there would be enough personnel and hardware to slow any incursion as much as possible. The purpose of the 2nd perimeter is to mark the line in the sand at which the enemy is to be stopped. The 1st perimeter is a fail safe so that if the enemy breaks through the 2nd perimeter and approaches the 1st, security personnel will hold this line until all essential personnel are evacuated.

I went through all this because it applies to structure as well personal security. Of course, we will make a few modifications. Yes, I know that not all structures will give us either the shape or space for circles. Nevertheless, despite these problems a concentric security grid will do us nicely as attempt to protect our homes and persons.

Personal Security

We often assume we are safe in our homes and generally, that assumption is true. Nevertheless, the individual at the door might turn out to be the insurgent we said would never visit our abode. Of course, the risk increases dramatically when we leave our homes to wonder in the real world nevertheless, the principles are the same. The person who is walking by us, smiling at us might just turn out to be the insurgent we again never thought would violate our space.

Violate our space. This is a phrase we use very often when someone enters a particular area getting to close to us personally. In this article we will define the length of “our space” as thirty feet using our body as the epicenter in a circle. Generally both the Police and military define close quarter battle or combat (CQB) by space. This space is the distance between touching the insurgent’s body and thirty or so feet.

The three concentric circles around our body will determine the level of the threat. The inner most circle will be our body. This is red. Red is fight or flight. No one ought to get so close to our body as to touch us without our permission. Our body is our property and the space aroundBo in circle it is inviolable without permission. No one has the authority nor can anyone give the authority to another to violate that space unless we act in such a way as to violate our civil trust. Any threat that enters into this inner circle ought to be treated as “grave.” If such a threat invades this area you ought to be ready to match the threat’s force level and be willing to use deadly force if necessary. When a threat enters and touches your person it is time to attack! No insurgent who gets this far ought to be there for more than a few seconds and he ought to be terrible pain when he leaves assuming he is still breathing.

The middle circle extends from the body to the tip of the finger as you extend your hand out in front of you at a 90-degree angle. This is orange. There are many and legitimate reasons why a person might invade this area. So, not everyone who invades this area will be an insurgent nevertheless, an insurgent cannot attack you personally without going through this area in CQB. Orange is heightened awareness. When someone enters this area you senses should perk up because this individual might be the insurgent you never thought would attackBo In circle1. Nevertheless, there is no reason to be act like a gangster. Today, it seems to be the norm for people to walk around with a snarl on their lips so as to show the world how bad they are. Smile, be courteous, be kind to the individual who enters this space because it might be in error. Leave a friend. If the individual is an insurgent, you will know but you will have already prepared to meet such a threat! If it is a threat, attack!

The outside circle extends from your outstretched finger to about thirty feet. This is yellow. The fact is you cannot really watch all the area that you need and to be able to operate effectively. So, narrowing down the area to the space defined by CQB allow us to more easily see a threat that might be lurking, ready to attack. Yellow is awareness. Two important things about this circle. First, you know there are people out there and the vast majority of them are merely going about their business as decent citizens of this nation. They would not, could not hurt another human being on purpose. But it is in this sea of nice people that lurk the insurgent(s). The insurgent(s) is going to act a bit differently than the others in this circle. Often, we are keenly aware of the individual who sticks out in such a crowd and we keep our eye on them. Nevertheless, he may smile, look helpful, seems pleasant, say Hi! and might even dress well. What will set him off, what makes him different from those in the sea of niceness is that he is intently focused on you. You can see it in his eyes, his movements. Being able to spot a real or possible threat within the third circle gets you a distinctive tactical advantage.

Often, when I talk with gun owners about supplementing their carry with hand-to-hand combatives they respond that all they need is their .45. The above ought to show how ludicrous such a statement is. Specialists have shown conclusively that it is nigh impossible.45 for a person who is carrying concealed to draw his weapon, take his stance and shoot an attacker who is attacking within thirty feet. Yet this distance defines what is considered close quarter combat. If a person is really concerned about their health they need to understand the perimeter concept and possess not merely a handgun but a knife and a form of hand-to-hand close quarter combat.

If you are situationally aware of your surroundings and you see a possible threat outside the third circle you have time to prepare to meet it. This could mean pulling out your handgun and hiding behind something you are carrying. If you are forced to take this position then (1)Gun in butt pack make sure there is a round in the chamber, (2) keep the safety on if your weapon has one but your finger on the safety to release if the individual gets close to your inner circle and (3) keep the weapon pointed at the insurgent. It will not do any good to keep the weapon pointed somewhere else if the possible threat is trespassing into your territory because you may not have the time to reposition it.

If you have a knife, you could also pull it out as well and securely hide it behind something you are carrying like a coat or bag. Do not slash because clothing will mitigate even the sharpest of knifes. Stab. So, keep the point of the blade toward the insurgent if you must strike stab, stab and stab again.

Where does this system fail? Where most do. If the criminal has a weapon like a handgun or rifle then he can take you out without entering your space. Nevertheless, this is a different type of combat and goes beyond how to fight in close quarter.

Structural Security

In this case, the size of the circles will be larger but the principle is essentially the same. I realize there are different sizes of property which take on different shapes. So, the houses very closeconcentric defense system will be modified. The wider your property and the farther it extends from your home structure the easier it is to protect. Often in the city you have houses which are separated by a mere twenty yards. In such cases, it is more difficult to protect your property because the insurgent can sneak up on you more easily.

The 3rd circle, the one farthest from the structure, is the point where you look at a person and say, “What is he or she doing?” It is not that the individual is necessarily doing anything wrong because he may have a legitimate reason for crossing onto your property, temporally. Nevertheless, this is yellow. However, let us discuss night time. If a possible insurgent crosses this line he or she ought to think to themselves, “This person is Tree lineprepared.” Specialists often speak of using light sensors triggered by motion around the physical perimeter of your house to ward off potential insurgents. But by the time an insurgent(s) tips a motion sensor he can almost if not actually touch the structure of the house. So, by the time you get up to check on the situation, if you do at all, the insurgent(s) could have hidden themselves out of sight waiting for darkness to return. Instead, use light motion sensors on the farther perimeter. Granted you might have issues with critters who come searching for home and food. In this search they might set off the perimeter lights. But if you reset the calibration you will make it more difficult for animals to disturb the system.

The 2nd circle is where you want an insurgent who has somehow breached your 3rd circle to think about his life. This is orange. As long as society is basically civil we want to use only non-lethal warning systems. This circle ought to be loud and bright. There are a number of Tree line1books which provide different methods you can use. One trap is to use a rat trap and hook to it an empty shotgun shell and when tripped will set off the primer. If the insurgent is stupid or determined enough to dismiss your warning at the 3rd circle, what awaits him at the 2nd ought to make the insurgent(s) realize that you are very well prepared and aware of his approach.

The 1st circle is the structure. This is red. If the first two circles are set up and properly the insurgent should never make it to this far. If the insurgent(s) trips the warnings at the 2nd circle then hopefully (1) the insurgent(s) will turn and run, (2) you are now prepared to meetCountry home this potential threat within your house and (3) the police have been called and are arriving. But lets say the insurgent(s) gets to the structure or you have not prepared the warnings on your property and he slips up unawares.

In this case, there are a number of sections in the house which need to be fortified. The primary entry points of a house are the doors, windows and fire places. Of course, the insurgent could set the house on fire but generally this will not be a problem unless society has collapsed. If society collapses then everything we have discussed is worthless because the type of insurgent of which we speak will be of a drastically different mind set. Your response to such an insurgency will have to be drastically different as well. I will speak in about fortifying your doors, windows and other soft entry points when we discuss what happens when CQB enters your home.


The point of the concentric defense system is two-fold. The first thing this defense system does is gives you a defined space that you can use to determine the status of your security. This is true of both personal as well as structural security. Secondly, by using the 3rd (furthest circle) and the 2nd (next furthest) circle as barriers to repel the insurgent(s) the insurgent(s) should never reach the 1st circle which is either your body or the structure of your house.

I hope this information helps. If you have any questions or additional information please email me at

  1. jcoles says:

    Great overview, Bo!!
    I’m a stand off oriented fighter … that’s why my defensive zone starts 1,200 feet out from the house … I have fans of fire laid out at different range & angles … a noisy & dangerous guard dog and controllable lighting within 250 feet of the house …

    By spring I’ll have motion activated video installed …

    For close in work I have a number of tools available … none would be pleasant for an intruder …

    • Bo Perrin says:

      Thanks, Jim. Your opinion and insights are always valued. Your place sounds secure and of course, as you said you have the tools necessary if someone does breach your measures. I am going to add to the Perimeter Security article later and discuss what to do with blind spots both in the yard and around the house.

  2. CptJera says:

    Good work, sir. Will be sharing with my neighbors at next meeting. The info will help explain to them the reason for preps we’ve taken on our own property as well as how/why they should take steps for protecting their own. Thank you for sharing this with us.
    As for blind spots, the task of clearing a right of way for power lines coming onto our property has given us the opportunity to clear many blind spots created by low brush and the poles themselves will be perfect for elevated placement of wireless cameras. There are only three “easy” approaches to our structures or even onto the central part of our compound, our 2nd circle. The two coming in from wooded areas have clear signs marking the outer circle along the trails and warnings of the use of physical and deadly force should an intruder choose to proceed. Not a very good idea for anyone violating our space, I can assure you. If they are able to retreat, they WILL need to assistance to do so.
    A very important point to be made here regarding the use of force: check your local laws as regards booby traps. I have found that some jurisdictions consider them illegal regardless of the warnings you may post. In such cases, the lethality of your traps will need to be adjusted.

    • Bo Perrin says:

      Hello sir. Thank you for ready my materials. I am glad they will be of help. Speaking about blind spots, in one of the next articles I pen I am going to deal with the typical blind spots that many residents encounter in their yards and around the house structure itself. I like the “kill zones.” Herding insurgents into a single area is great way to effectively and quickly eliminate the threat. I understand your point about the “booby-traps.” I did try to make it clear to everyone that we still live in a civil society so the warning instruments ought to be non-lethal. But I will reiterate that point in the next article on perimeter security. Again, thank you.

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