What does Ikken Hissatsu mean? 'To kill with one blow.' This is a controversial topic and there's a whole lot of stuff on the internet about it. This is just my personal take.
First up, let me make it quite clear that I do not believe such a concept belongs in today's Western dojo's, especially where there are children students, for obvious reasons. For them, the more apt concept to follow would be, 'Kisshu fushin.' The literal meaning of this is, 'Demon’s hand, saint’s heart.' It's the peaceful warrior concept; a peaceful person on the outside, refraining from violent behaviour, and a warrior on the inside, with the mental toughness to handle life's problems with courage, honour and dignity.
My argument here is that true karate-dō can be nothing else but Ikken Hissatsu. Why? There are many reasons, but here's three that I'll offer here, now:
Karate-dō stems from a time when the common man was not allowed to carry weapons. That's why many traditional weapons we see today were fashioned from farm implements. I'm no expert on this, but tonfa, nunchaku and sai all appear to stem from the farm-yard. In lieu of a farm implement, karate-dō training, as the empty hand way, focuses on transforming the hands and feet into weapons. Just listen to the descriptions; knife hand, axe kick (foot), spear hand ... to name but a few. If you attack someone with a knife, an axe or a spear, do you seriously expect them to live?
We know that the power of karate-dō comes from the hips. We hit with the hips, we punch with the hips. A critical aspect of a good karate-dō punch is hiki-te, the returning fist, which comes back to the hip line. This is a well-practiced and proven method of delivering a very powerful strike. But the time involved to reset and repeat the process, inclusive of hiki-te, is perhaps too slow. So, again, this implies that if the technique is only going to be fast enough for a single strike, then it better be decisive and final.
The round trip for the fist, from hip to target and back again is a costly one in terms of time unless one is aiming to deliver a single, terminating blow. Consider the 'straight blast' method of delivering multiple hand strikes. Many strikes, with power, in a very short space of time; where the hands rotate around a very limited axis out in front of the body, never returning to the hip and never leaving the body uncovered. Maybe not intended to deliver a knock-out blow, but it will keep an opponent occupied and backpedalling. A karate-dō punch rotates around the axis of the hips and at times leaves the body wide open for a counter-attack, but once it's on its way, there's little that can stop it. Using a military comparison, there's a big difference between a sniper's bullet delivered with surgical precision from a 1000-yards and harassing fire from light sub-machine guns at close range. One is designed to take a target out, with extreme prejudice, the other is able to keep a targets head down and scurrying for cover.
As an example of what it takes for karate-dō to be effective, take a look at the video clip 'Jiu-jitsu vs Karate' linked at the foot of this post, which personally, I don't find at all conclusive (it's not my intention to pit one martial art against another here), but merely farcical. And here's why.
The rules of engagement meant that the jiu-jitsu guy could use his techniques to their fullest extent, whereas the karate-ka couldn't. Because, if he could have, and was good enough, the jiu-jitsu guy would have indeed (arguably) still have ended up on the floor, not in control of the fight but in serious trouble. For the karate-ka in this video clip, it would be similar to sending a soldier to war with a rifle and giving him a pack of dried peas for ammo.
The other important point here is that the jiu-jitsu floor techniques are highly effective against a single opponent, but not if you're facing off against two or more. That's where a striking art like karate comes into its own. As long as you can stay on your feet and deploy your weapons effectively, you stand a fighting chance.
Sensei Frank holds a 4th Dan black-belt in Shotokan karate and began studying karate in 1974 in the UK. He was awarded his 1st Dan in 1980 by the Chief Instructor of the Thames Karate Federation the late Sensei Ray Fuller. His first teacher, Sensei Paul Masters, was the former Chief Instructor of the British Karate Federation and a student of the late Vernon Bell. Widely regarded as the father of modern day karate in Britain, Vernon Bell was the first Briton to be awarded a karate black belt in 1957. A senior student of Sensei Shahab, Sensei Frank is also the Head Instructor of the Shotokan Karate-Do Upper Harbour dojo, based on Herald Island.