The sides in this game were never meant to take armed civilians into account.
In the past iterations armed civilian units were always under either west, east or resistance sides.

Mission makers need to take that into account when making missions with armed civilians (if you absolutely need a fourth hostile side that is).

As to your point that AI should see armed civilians as a thread I'd like to note that there are some countries where it's normal for civilians to be armed in public (Pakistan as a non US example).

This would get out of hand if they did shoot at civilians who are armed/shoot at them. They would probably switch to a side that is an enemy side to the person they shot which would make the civilian allied to that side...

@Grumpy Old Man

"The sides in this game were never meant to take armed civilians into account."

Then why AAF shoots in the civilians!?

"As to your point that AI should see armed civilians as a thread I'd like to note that there are some countries where it's normal for civilians to be armed in public (Pakistan as a non US example)"
My friend, events in the Arma3 are far from Pakistan.

Events of Arma3 does not happen in Pakistan, note this) I think in Europe it's quite the opposite. Yes, maybe soldiers should not respond on civilian with a weapon in hand, but if this civilians attacked the soldiers, then should be an adequate response!
In the game the AI shoots even in the Union soldier if this soldier shoots allies!!!
So why is this same soldier must not shoot at civilians who opened fire on the Union troops!? What we have today in the game looks stupid.
Measures should be adequate!

• PS: This issue is not possible to create a mission with the participation of armed civilians.

AAF shooting at civilians needs to be investigated further, do you have a quick reproduction mission to see what exactly is going on?
Might be related to the weird side relation that I've been experiencing in the past:
http://feedback.arma3.com/view.php?id=20036

You're right about the reaction to armed civilians, soldiers should react in a proper way, but as stated before, the game works in a way that the civilian side would always be the "no threat" side, you shouldn't take the meaning of "civilian" literally.

The civilians in A3 also run a different danger.FSM and won't act in a proper way either when being engaged, they will just try to flee or hide instead of trying to fight back.

If you want a proper reaction to armed "civilians" just add them to a side other than civilian.

"do you have a quick reproduction mission to see what exactly is going on?"

Added video example. There is no need to create a repro mission.
Try to repeat what you see in the video example. This quickly.
Any faction (exclude AAF) will not respond to the attack!

Thank you for the report!

Civilians are on the same side as Independent and will only become "renegade" (https://community.bistudio.com/wiki/sideEnemy) by killing friendly units (Independent and those that are assigned as friendly to Independent in the Intel tab)

If civilian unit becomes "renegade" (sideEnemy = true), then any other unit in the game will attack.

Civilian unit can't become renegade by shooting at units that are "enemy" to the independent. To solve this you can set the Independents as friendly to Everybody in the editor in the Intel tab.

So even though civilians are on a separate side, they act "with" the independent side?

@oukej

"To solve this you can set the Independents as friendly to Everybody in the editor in the Intel tab."

Unfortunately, this is not solution of this problem!
The AI should behave adequately always, regardless of the settings in the editor.
If the AI comes under attack, he should always respond!
The AI should not behave like robots.