I think that the fundamental external conflict that Eliezer experiences is the struggle to survive. From the most basic point of view, Eliezer is being hunted or persecuted because of his ethnicity. In this, Eliezer finds it a struggle to survive. Eliezer struggles to survive. The Nazis and other camp guards that abuse and demean him represent the forces with whom he wages external conflict. Eliezer is not assisted by many in the outside world. This makes the identification of Eliezer's external conflict rather plentiful in terms of examples from the text. When Idek beats Eliezer, it is an example of the external struggle that makes him fight for survival. The time spent at Birkenau, in the moment of selection where his mother and sister are separated from he and his father would represent another moment of external struggle. As his time in the camps increase, Eliezer's desire to survive and live becomes of vital importance to him. This makes his struggle against the world and the forces that seek to deny him his life incredibly important. In this, Eliezer's struggle to live against the forces that wish to take his life from him becomes a dominant external struggle in the narrative.