Allied unity and an American us-or-them outlook

Why was a show of allied unity so important to the United States despite criticism of its conduct in the 1960s?

An us-or-them outlook made solidarity important, with anti-communist paranoia and the rise of McCarthyism offered as an explanation.

Visible allied unity fitted an American us-or-them view of the Cold War. The paranoia associated with that outlook helped Senator McCarthy rise to prominence. Clarke recalls relatives who lived in the United States at the time and returned to Britain with an unfavourable impression.