It should be remembered that France and the UK botched just about everything in the 1930s, failing to work together effectively to confront rising Nazi German power. Trying to blame the USA (which was not a member of the League of Nations and which had explicitly distanced itself from European power politics) for their own failings is pathetic.
Yes, who was the person declaring “peace in our time”. The UK/France appeasement in one form or another went on for over a decade before the war. To the point of sacrificing other countries for it. Poland, Czechoslovakia, etc.