After their liberation, most Holocaust survivors experienced survivor's guilt, which is the mental guilt having to do with the fact that some people survived the event and others did not. Essentially, the survivors felt guilty that they survived the Holocaust while so many other people didn't. This is common with traumatic events like the Holocaust as well as wars.
I hope this helps.
Because it failed to overthrow the russian monarchy tsar
I am almost 100% sure that it is activist leader.