There is always another choice.
Tatsu: Sometimes, the mission is not worth the cost. You know that. So, why are you still doing what he asks?
Oliver: Because if I'm wrong, if I'm wrong then all of this is for nothing. Do you understand Tatsu? I left Felicity, I left my children. So if, if The Monitor can't fix this and if he is not here to help then all of these things that I have sacrificed and all of the things that so many other people have already sacrificed will have been for nothing! I need my family to live. Which means that I need this to work.
Tatsu: You are risking too much.
Oliver: There is no other choice.
Tatsu: There is always another choice.