Depends...but if you read Ellis Amdur's material, he often stresses that at any stage in the waza, you should be able to strike (effectively). I've often heard that you should be able to strike while being safe from counter strikes as well.
nice, that's good to read. when prevention fails, knowing that I can strike hard gives me the confidence to see a way to not strike at all.
when I intervened to stop a fight (well, a beating in progress) in a Richmond bound BART train one afternoon, I was glad that I had years of Karate (and Hapkido) conditioning as I seem to know where their hands were (and that weapons were not being drawn) and that perp seem to know I was ready to strike (opening with an elbow cross to face), but holding back. Would also be useful to have a less damaging waza in my survival "vocabulary."
I am looking forward to Aikido enhancing and integrationg with my Karate and having a new fun outlet for exercise.
off topic: so far, a 90 min BJJ class is the most honest sporting contest and rigorous exercise I've tried, but a bit limited in scope due to their on the ground focus.