Here's a scenario to think about. It is most often the way it happens in real life.
Someone for some reason want to hurt you. Let's use the bar scene, it's a good one.
You want to keep maiai right, so you can intercept and blend and do aikido if someone is being aggresive with you. Well guess what the first thing they're going to do is? They're gonna get right in your face, and I mean up close and personnal. So what do you do?
As an Aikidoka, do you establish maiai? Well, they're gonna just get right back in your face. So do you just stand there and calmly blend your face with their fist when they decide to punch you? Then try to reestablish maiai so you can wait for an opening?
In my opinion, some Aikidoka get this vision of what it's like to be in a conflict that is nowhere near the truth.
I've pummeled people before (never by starting it) and before the confrontation/altercation you should take the initiative to gain as many advantages as you can. Your attacker will if he's any good. They'll try to back you into a wall, a corner, get you riled up, get you alone, catch you with your back turned, anything.
You should always have the initiative, even if you do nothing.