‘There is no first attack in karate’ is repeatedly brought up on on social media and I think is often misunderstood.
The ‘kara’ in karate means empty, like in karaoke (empty orchestra). Its use here is as in the zen ‘empty of intention.’
A skilled karateka is a powerful peacekeeper, with that essential ‘soft front and strong back’. They don’t start violence, like any law enforcement officer, but handle it when it arises.
In discussion so many people naively still think that karate (traditionally a stand up grappling art) is ‘block and punch’ in self defence, it’s far from that.
In most confrontations these days the phone cameras and cctv are recording, so a ‘pre-emptive strike’ probably means prison and could be a panic over reaction.
A skilled practitioner allows the attacker to make the first mistake by protruding and/or leaning and will ‘receive’ the attack with the soft front and negate it spontaneously using a multitude of effective skills one of which could be a simultaneous strike, depending on the environment and nature of the attack.
The people that deal with violence every day in law enforcement and the security world utilise emotional intelligence, soft skills and physical restraint when necessary.
Use intelligence, hone your skills and strategies and work within the law. Remember that you might have to explain your actions in court in the cold light of day and will probably be on video.
Stay safe.

