taekwondo is the only fighting system proven in modern war times. I always hear from military instructor to train like korean marines in Vietnam and Korea War. Undefeated by arms and hand to hand. Look up operation van buren. They document that firsthand US & UN soldiers found VC with unhinge jaws,crushed skulls,caved chests from encounter with 13 korean marines vs. battalion.David ‘Crow’ Losieu learned and used tkd, Fedor imcorporated into his training to improve his kicking.The place where i used to go taught tkd/hapkido/judo and they mix well together kinda looks like a ufc fight with heavy striking and grapling/ground game when we spar.But we also learn knife and gun disarming techniques.I know there are a lot of schools that might as well be a belt factory but not all are that way.Now i do muay thai (1 week)and the response i got from my first sparing experience was crazy beacause at tournaments most tkd places suck.