IF a knife was used, you use what force is needed to stop that threat. A deadly weapon can mean using whatever force is necessary. You can try talking the person out of using that knife, which might work, talking sense into them, but if they come at you, you do whatever you can to stop them. it doesn't mean choking them until they die but disarming them from that knife. These are the measures one can take........Legal Standards for Self-Defense Imminent Threat: The danger must be immediate and happening right now. You cannot use force for a threat that is past or purely speculative. Proportional Force: The law permits the amount of force needed to stop the threat. Because a knife can cause fatal harm, severe or lethal force to neutralize the attacker is usually considered proportional. No Provocation: You cannot have started, provoked, or escalated the fight. Duty to Retreat: In some regions, you must try to run away safely if an escape route is available, while "Stand Your Ground" or "Castle Doctrine" jurisdictions allow you to protect yourself without retreating in places you have a right to be or inside your home. Force must also stop the moment the attacker is no longer a threat..Practical Survival Realities Escape First: Running away or creating distance is always the safest and most effective option. High Risk of Injury: Knife attacks happen extremely fast. Physical blocks and disarms are difficult, and most people get cut or severely hurt during close-range knife struggles. Improvised Shields: Putting objects like backpacks, chairs, or thick jackets between you and the blade can help block strikes and buy time to escape. My ex came at me three times with a knife, as she did with a couple of others (her words and her family's), and I talked her out of it twice and her sister got in the middle the other time. Thais are quick to use knives so this is a legitimate threat here many are aware of. This is what the court will look at, to see if his self defense explanation holds water. the burden of that proof being on him, as he took it to the extreme. Coming at someone with a knife is not a minor threat, as knives are used daily to kill many people, and most anyone can kill a person with a knife very easily.