Two things in your case are commendable, you were situationally aware and you can run. As stated by others, some of us older guys can’t run like we used to. I’m on that category. In my case I would not turn my back, as with working with wild animals, face them you gain some respect, turn your back and your dinner. My question would be if you couldn’t make it to your car and use the door as a barrier, would you have done like I think others would have done and initiate plan B? As with any situation of the kind, we have the luxury here to think about something that in real life, a life and death decision must be made in milliseconds. So I’ll just say that if and when it happens to me, If I survive it as you did, I’ll let you know how it all turned out.
From what was said above, I’m reminded of Crocodile Dundee, “that’s not a knife, This is a knife!”
Escape if you can.
Give him your money if you can’t.
Draw and get on target if the money doesn’t do it.
Pull the trigger as a last resort.
All within three seconds.
I concur on the running
some days its hard to get out of the chair 
our cpl instructor said if their with in 21’ its a good chance of getting cut
Which side of the door were you standing? I am thinking if on the exterior side of it, then good deal. If on the interior side, then he could have used the door to smash you with it - unless you were standing clear of the swing?
I just wish to add I’ve seen enough Vid’s from you folk’s on You Tube where the little bastards chase you down if you attempt to ‘Escape and Evade’ , run away whatever that this would not be an option even if I had real legs. And no way would I consider this if I was w/ someone or kids.
We tend to over think what if’s here when it was mentioned above numerous times you don’t have time to figure out your ‘options’. (3’ isn’t dik). (10’ gets gobbled faster than you realize) Just remember the video of the Cop and the Retired Vet on drugs or mental my friends. He didn’t stand a chance (Alamogordo, NM I believe is where it happened). His name is now on the Cop Memorial in DC. What it boils down to basics (for me alone) I Train for this exact situation and sorry to admit for some here it’s SURVIVE FIRST! END the THREAT ASAP. That means shoot, NO Hesitation, No Flinching.
Like it or not call it brutal or too violent what people fail to take into consideration here is these pieces of shyte often don’t do this alone anymore. These animals run in packs. PREDETOR’S. I will end the immediate threat then do a scan IMMEDIATELY 360 and then If clear I will consider my next step. At 3’ a knife might as well be a Gun. Enzo said it clear recently a knife slash along the arm (Just on the arm) can be fatal. Imagine an attacker slashing wildly , possibly getting in your wheelhouse before you can pull your gun? It comes down to Situational Awareness and Training as it ALWAY’S does. If you can identify the threat early, Don’t go to Stupid places, do stupid things with stupid people you are ahead of the game. There are parts of my city I just don’t go now, and Albuquerque is a tame city compared to some. I don’t know how people live in some of their cities these days. God bless 'em. They have no choice. But I do. Making smart decisions, not drawing attention to myself and being aware I feel I am ahead of the game. I haven’t gone shooting in a while because my Internals were screwed up and my local range made me ‘feel’ uncomfortable because of attitudes and *-hole Range officers. Well, I just had to suck it up and go. My skill level was damaged because I didn’t go for a while. Proof on paper I sucked. Yes, if it was a kill or be killed situation the attacker would be dead, but my groupings sucked. I had to go back a couple of days later to tighten them up where the groupings weren’t measured with a ruler. It happens that fast for me. Muscle Memory only lasts so long. Train up folk’s, get your mind right because my opinion only it’s going to get real bad real soon.
Military Installations are already being ‘Probed’. Happened @ Quantico just last week. This isn’t Tin Foil Hat talk. They are here, and they are near. Pudding already KNOWS he’s in trouble. People aren’t just going to hand Orange the keys to the Big Chair willingly. They are addicted to the Money and the Power.
If you can have enough Guns and Ammo (well, there’s never enough guns amirite?)
A ‘Black Swan’ event or worse is quite possible these days
What were these (2) Jordanian’s trying to accomplish Invading this military base? They weren’t there to change of old chips @ the PX?
Be Alert
Stay Frosty
WWG1WGA
So, walking toward… or worse, away - with your back to the armed thug, is somehow a better answer ?? I have a difficult time understanding people that propose these type of solutions… “Well, I would have…” or … “You should have…” Coming from someone who has never been in that “Type” of situation, I truly wish you would not propose your opinion of a proper action. Having had extensive training in the military, and unfortunately a few life experiences on active duty, I can say definitively that unless you have a CLEAR and DEFENDABLE line of retreat,… That is the surest way to a body bag. Thousands of trainees are presented with a dilemma of drawing a sidearm and firing 1 round to defend against a knife wielding attacker at 20 YARDS. The catch… you don’t know which of the 5 civilians is the attacker. Even fully trained officers fail 90% of the time. Humans simply can’t process and react fast enough. One of the best actions is the overwhelming in their face “Shock and Awe” approach. In these situations, your only job is survival. PERIOD. Any time you are threatened with a weapon, You must survive. Present every defense AND OFFENSE you have to save your life. I would rather be judged by 12, than carried by 6. If you honestly are in fear of your life or that of another, the only rule of the game is to live. There are hundreds… thousands of military graves filled with soldiers that gave the enemy the slightest thought of a non lethal response. It never ends well for the innocent or trying to follow some theoretical “rules”. You can debate that later in the courtroom. The alternative is the morgue.
If in all your ‘Extensive Training’ was Reading Comprehension part of your training?
Please re-read what I posted (again)
I will NOT go line by line with you but I clearly wrote (My opinion only, For me etc etc)
I don’t tell people what to do and how to do it. EVER
And I won’t even touch upon
This statement alone proves to me you are ill-informed.
Have a nice day Brother
We shant be speaking again, EVER.
Sooo… This is your first post??? Really??? Come in and piss people off you don’t even know. 
Retreat is often only a viable option if you recognize the threat soon enough to give you time to retreat and you have somewhere safe you can retreat to.
In the two car jacking attempts I faced retreat was an effective option. In the first one I used the threat of retreating with my vehicle through one of the car jackers to get them to back off. With my second one I retreated back into a store before they could corner me.
But even when the threat is close retreating behind some nearby cover can give you an extra moment to prepare a response and an advantageous position to respond from should the threat decide to follow.
Maybe I have to re-clarify my position again folks
“FOR ME” MY OPINION ONLY" on MY TITANIUM LEGS"
Retreat is not an option.
The last thing I need in a possible shoot is falling down
going Turtle where then the attackers can pounce. That’s all.
Whatever works for YOU is up to YOU.
Seeing what people propose and what others think of those proposals is one of the key benefits of this forum. Even those with a lot of experience haven’t faced every possible scenario.
All of us can benefit from game planning scenarios. If we think about and more importantly practice responses to a variety of scenarios our bodies are much more likely to be able to respond quickly and effectively to a similar threat. If we are faced with a situation we haven’t thought about or trained for then it becomes much more likely that our response will be slower than it needs to be. Or even worse our brains and bodies could freeze when faced with something we have never before imagined.
I’d rather have people here poke holes in my strategies than to have a criminal on the street poking holes in me due to potentially flaws in my strategies and preparations.
I can agree to a point but the rules aren’t theoretical. There are significant difference in allowed actions between a soldier on the battlefield and a civilian on the streets.
Neither in a grave or in a jail cell works for me. In either case I can’t be around to support and protect my family.
He has tons of close combat experience in Mogadishu there new guy. You know nothing about him or anyone else here. He has went through hell. Maybe get to know us a little before you start spouting off.
Forgot to add:
Welcome to the community @Les23 . I look forward to hearing more of what you have learned from your experiences.
Though your first post seemed to take issue with something @Don102 had said, it sounds to me like you may share some common ground with life experiences and points of view.
A easier statement would be “stop drop the gun or I will shoot.”
And if you are absolutely forced to shoot go for center of mass to lower the chances of a through and through and continue shooting until it is no longer safe to do or you run out of ammo.
The exception to that is if the guy is down don’t walk up to the body and empty your mag into it, that can turn the table in you taking it from self defense to intentional homicide.
The state might claim you where not interested in defending yourself, you just wanted to get even and are trying self defense to get away with it.
I was on the inside as the window and metal provided me some coverage, if he slammed the door onme it would have hurt, but he would have ended up shot.
Sorry, I couldn’t help myself 
I’ll toss my wallet accidentally missing the guy so he has to backup and retrieve it, hopefully giving me enough time to get away.
I always have a little money in my wallet and my WIX gas card and debit cards, all of which require a pin to be used and can be quickly cancelled, conversely I carry the majority of my money in my left front pocket and a thin leather pouch in which I keep my CC’s which do not need a pin plus my other ID’s.
My ID’s are tougher to replace, my DL I can order on line for $6 or so but it takes a week to get a new one, I can recite my DL number so that would help a little if I was pulled over, but the real trouble was my AT&T ID card, I lost it once and had to spend a day over at asset protection filling out forms giving a statement and answering dumb questions like is there anyone in my family who might have swiped it to cause damage to the company in any way, then sitting around waiting to have a photograph taken.
But at least the replacement was free, though there was a second problem and that made for a lot more trouble, in the same pouch was my access control card which unlocks most of our CO’s and a number of macro cell huts in Broward County when I told AP I had lost that as well they went through the roof, it seems that made for a bit of work as the way they set it up it for multiple buildings is to issue a new card with all access, then manually lock me out of buildings I have no reason to be in like stock rooms other the one I work out of.
They really gave me heck for having it in the same pouch as my ID even though that was how they issued to me my I and access card all in the same pouch.
I had enough of the guys crap and told him if you don’t want me to carry them in the same pouch don’t issue them to me in the same pouch as somebody in this office did when I was hired on by the company, that shut the guy up.
Now want to talk about tight on the ball corporate security, after 24 years in Core Network (Special Services the SS) I was advised to take a lateral over to Wireless I wasn’t told why just do it, so I and a few other techs I got along with slid over to Wireless, 6 months later we discovered due to a technology surplus we would have lost our jobs or would have to transfer off to who knows where, the manager who told me to do that saved all of us a lot of grief.
Fast forward to 2019, I received a call from a tech who I used to work with in Core Network, he had become a manager and wanted to know if I wanted to go out to lunch at a rather nice restaurant paid for by the company, a tech we worked with for many years was retiring and as part of that retirement was a retirement lunch paid for by the company, well a free lunch at a nice restaurant with a buffet all paid for, yes count me in.
I was told to come to the yard and I would ride with my manager to and from lunch, when I got to the yard instead of pressing the intercom button to have the gate opened I tried using my access card which like my ID was never turned in when I separated from Wireless, no one asked for them so I retained both.
I held my access card in front of the reader it beeped and the light turned green then the gate opened.
So called Asset Protection never removed that card from the system, such on the ball security.
For more fun I clipped my ID to me shirt pocket let myself into the building and found my manager, we shook hands he saw the ID and asked why did I still have the card it was supposed to be turned in when I separated, my answer was simple no one asked for it so I retained it and my access card which by the way still works, which is how I got into the yard and this building and if I need some wire or stuff I’ll bet it unlocks the stockroom.
He shook his head and said something like corporate security what a bunch of stooges.
Now as for left or right and front or rear this is why I use my front pockets.
I learned a long time ago most men keep their wallet in a rear pocket making it easy to snatch and run off with it, I keep everything in my front packets, it is easier on my back and harder to snatch.
That’s because trying to reach in either of my front pockets without me noticing it and stopping is easy, the only exception to that would be if the person reaching in there is a 30 something hot looking female and her hand better slide past my wallet lower and more to the middle of my body otherwise it’s out of there and don’t touch anything.
And don’t even think of trying to reach into my left front pocket, I’m real sensitive about that side.
Now if she in insisted about doing either that’s not a problem I’ll get a room at a nice hotel and we can start getting there by taking a nice warm shower together. 
OK to me, you said:
My first impression? You’re screwed, that arms/knife length. But that aside, I for one am all about the passive, retreat call the cops approach but not for a person that is 3 feet away, with a knife.
Now if it all occurred
after I got to a better defensible position , I’m still reacting the same, he has a knife in hand, he is/has pursued me, he see’s I’m reaching for something, right now with hand on holstered firearm my first shot on target is 1 about second, that’s how long he has to get into OBVIOUS retreat.