This statement is very important for the movie plot. Walt is tells a war story from the time he fought in Corea. He is also talking about knowing something is risky and doing it anyway. He talks about finishing the things you start. He claims he has blood in his hands and it's better for Thao to keep himself out of what's about to happen. Walt knows he is in great danger and tries to protect Thao. He then confronts the gang and is killed in coldblood in the middle of the street while he pretends to draw a gun from his jacket.
Then you should say something about yourself and your relationship to this subject. Fear, commitment, protection. You could also say something about facing problems with different angles or doing things not the way you are expected to.
