Many weaker people look to the powerful for assistance, many more resent their power. The first set will damn the powerful if they don’t help, the second will damn them if they do. Whatever America does, it’ll get shouted at. Human nature is human nature; all America can do is ignore the detractors and follow its conscience.
But do not ignore good friends, who’ll criticise from time to time. Friends’ criticism may sound like the carping of the resentful, but it is not. Constructive criticism is essential, it shows explanations unsaid, problems missed, … .