"If you choose to face Vader, you will do it alone. I cannot interfere." Thinking about this the other day, why is Obi-Wan unable to interfere when Luke confronts Vader in "The Empire Strikes Back?" By this I mean, is he a) literally not able to physically appear at the confrontation to either guide or help , or b) is he trying to scare Luke off from leaving his training? If it's "a," that seems like a strange Force rule. I mean he's able to make appearances everywhere. Is it some dark side energy that keeps him from appearing or aiding? If it's "b," that seems like he's really throwing a huge opportunity away. To let "our last hope" just run off to quite possibly be captured, die, or worse, be turned to the dark side and one of the things he comes up with is, "hey, I can't help you if you go." As if that's going to convice Luke to stay? Any thoughts on what the topic's line means? I cannot interfere.