The Threat Onion
If your armor ever stops a bullet, you've already lost.
While the recent focus on armor isn't necessarily a bad thing, a lot of it seems to be missing the bigger picture - and that's what we're here to talk about today. First, though, take a look at our good friend the Threat Onion.
The idea behind the Threat Onion is to remind everyone that stopping a bullet is far from your only line of defense - and in fact, if it ever happens, it's because there have been a series of failures in your other defenses! The only way to get to the heart of the onion is to first go through every layer to get there - so each layer has an important protective role to play.
Starting from the outside, your first line of defense is to not be seen. This can take the form of camouflage, clever use of terrain, or just not being around at all! Never underestimate the power of keeping your wits about you and getting out of there before things start getting spicy. Ultimately, if you're either not around, or the enemy doesn't know you're around, they won't be able to target you.
Next up is your second line of defense, not being acquired. The idea here is that even if the enemy sees you, they don't target you. This could be because you don't appear to be a threat (because you blend into nearby activity and look like a bystander) or because you do not appear to be the biggest, most imminent threat (in which case the enemy will be worried about that, not you). Ideally, not being acquired means the enemy sees you, looks right at you, and decides to ignore you because you blend in. Wearing obviously-military kit, being visibly armed, or otherwise looking important makes you stand out, and increases your odds of being acquired by the enemy rather than ignored. Do your best to blend in, and you won't have to worry about being attacked at all.
If not being seen or acquired both fail, your next best chance is to not be hit. Using mobility to your advantage, take cover, move around, and make yourself a difficult target. In military contexts, suppressing fire can be used here to keep the enemy's head down so that they aren't able to line up good shots on you. In either case, the best way to not be hit is to be highly mobile, make good use of cover, and keep the enemy busy and distracted.
If you are hit, the next layer of protection is to not have your protective equipment be penetrated. This is where armor comes in - but you'll note that if having armor means you're more easily seen, acquired, or hit, it can easily be a net negative. Being hit but not penetrated is your last resort when all else has failed, because being hit is never going to be consequence-free - not to mention that armor or other protective gear can't cover you in all places at all times. Armor has gaps, and you will always be taking a risk that when you're hit, it will be in one of those gaps.
After everything, your last possible chance is to not be killed. Assuming your protective equipment has been penetrated, this will mostly be a factor of two things: luck, and medical support. Depending on where you get hit, what you were hit with, and whether there are medically-trained comrades nearby (or you are able to self-aid), you may or may not survive. In no case is it going to be a good time - even if you're not killed, it's unlikely you will walk away without lasting health consequences. You'll also note that the factors here - luck and medical support - are not ones you can control in the moment (or, for luck, at all). The point is that if you've made it here, to the core of the onion, it means that many, many things have already gone wrong.
Keep in mind during all of this that wherever possible, you want to reclaim the outer layers of the onion. If the enemy is attacking you, changing your appearance so that the enemy can no longer identify you may let you leave the area at your own pace. Being able to hide brings you all the way back to the first line of defense, not being seen. Even if you've arrived at the inner layers of the onion, you should always be thinking about how to re-add more layers around you. This will almost always require mobility - going from "don't be hit" to "don't be seen" requires you to get out of the enemy's line of sight and ideally out of the situation entirely.
In conclusion: when you're thinking about protection, be sure not to over-focus on one layer of the onion, especially the ones closer to the core. Use the threat onion as a thinking tool to identify all of your options and plan for them appropriately. Will wearing this armor make you a visible target? It's likely a net negative to your safety. Will wearing heavy equipment slow you down? Consider what you can remove and go without so that you can retain the mobility you need to not be hit and to avoid or disengage from a fight (not be seen) if needed. Do you even need to be there at all, at least visibly? In the end, your best protection is simply not being where there is danger. Everything past that is a compromise that you should take the time to consider.