is it the duty of civilized people to take sides and interfere without reguard to national borders and sensitivities whenever other humans are suffering?

In 'Night' by Elie Wiesel, people stayed optimistic because some were so dazed by how starving they were and they were all kind of living in their own fantasy worlds because they couldn't accept reality. But in certain parts of the book people say to Elie "liberation is soon to come" and stuff like that. A lot of people just assumed that the next day everything would get better because they couldn't accept the fact that they were most likely going to die. Elie specifically stayed optimistic because he didn't want to die and leave his weak father, Shlomo, alone by himself. For your second question, many people on the outside of the ghettos and concentration camps didn't speak out because they were afraid to get involved and they didn't want to get punish for trying to help or support the Jews. Many people did care and want to help the Jews but were too scared to speak out.