Why does wiesel begin "the perils of indifference" by the u.s. soldiers who freed him from the concentration camp as a child?

If the US soldiers didn't free him, then he would have been dead in the long run, and wouldn't be capable to write all the books about his experience in the holocaust as he did today because The Holocaust was ignored during World War 2 because the other nations were indifferent and felt that it was laid-back to just put the problem aside. 

Answer

He reminds the audience of his experiences as a Holocaust survivor

The preamble sets the stage for the Constitution (Archives.gov). It clearly communicates the intentions of the framers and the purpose of the document. The preamble is an introduction to the highest law of the land; it is not the law. It does not define government powers or individual rights.

Establish Justice is the first of five objectives outlined in the 52-word paragraph that the Framers drafted in six weeks during the hot Philadelphia summer of 1787. They found a way to agree on the following basic principles:

"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America."

Explanation: