Did I give the right advice?
On the Bugei Sword Forum, the question 'how to deal with jabs using Aikido' came up. I answered to the best of my ability (since few others there seemed interested in giving an Aiki answer- they all wanted to subdue him with kicks and punches(which may be smart, but...)) but I just wanted to run it by some more experienced Aiki folks here to see if there was anything else I should have told him. Any way, the following is a cut and paste of my response.
It seems to me that if you're receiving a jab, you're too late with your technique. I do agree with the earlier idea that a jab doesn't offer enough commitment to properly apply most aikido techniques, but them getting their body within range for that jab certainly does. If you were maintaining proper Mai (safe execution distance) before the engagement, and reacted when they crossed this hypothetical line, that motion of their body is what you have to respond to. As soon as they cross your engagement line, you should react - and I'd be willing to wager that anyone that was coming in to punch at you will bring their hands up if you suddenly spring forward and to their side - thus giving you something to grab hold of. Then harmonize their head right into the ground. (Tenkan and Gaeshi, Atemi and Shiho Nage, etc - input your favorite distance closing aikido technique.)
The other response my Aikido training suggests is that when the jab comes, use the fact that the boxer is going to drag it back in with full force and speed. Get your hands up and protect the target they were going for, then as they draw back into their own center, you float in with them. As the hand goes back, you let it lead you all the way back to their center, then put an ate of some sort in their face, or (better choice, IMHO) sidestep and execute Irimi Nage.
The important thing to remember here is that their arm isn't the only source of energy in the situation. Their body had to move at some point to start this engagement- your body can move to react. If you move back, you can draw them out. If you move forward, you can force them to react (either forward or backward - whatever their training dictates.)
The defensive nature of Aikido, and the strength of using their force against them are tools for you to use - not limits to hinder you in a given situation. Don't confuse defensive with reactive. And if they don't provide enough energy, add some. Push them or pull them to start them moving. Use an Atemi or simply move your body to force them into a body movement you can work with.
In my experience, any attack with enough force to hurt me also contains enough force to hurt my attacker- it's just a matter of finding it and redirecting it in an efficient manner.
And what other people said should be considered too. An atemi to the attacking wrist may just be the disruption you need to cover your floating inside their attack to take them down. And while we don't teach them often - their is NOTHING wrong in my opinion with an Aikidoka kicking at an attacker, when doing so fulfills Aiki principles - takes you off the line of attack, unbalances your attacker, controls distance, makes his movement and attacks work against him, etc.
In my experience, any attack with enough force to hurt me also contains enough force to hurt( err, I mean, 'harmonize' *Wink* ) with my attacker- it's just a matter of finding it and redirecting it in an efficient manner.
But that's just my opinion.