Errr.Goomba:
"A) Everybody failed to recognize the threat Hitler really posed. Appeasement was rife in all the 'diplomacy'. The closer the Nazis were to moving into your back yard, the more seriously they were taken. No one took them seriously enough until they moved on Poland, and by then it was on. Germany represented no immediate threat to the US, and there was a great deal of 'wait and see' as a result of the last war, and the horrible economics of the day. As the fullness of the Nazi threat became clearer, that attitude changed and I defy anyone to question the scope and magnitude of the US committment to success in both the Europe AND Pacific wars."
There was concern about Hitler stepping up to the start of WW2.
Churchill was one of those.
Poland was the red line, and those who were serious were Britain and France.
Wait and see was the word for the US, and there were strong voices in Germany's favour abroad that time.
The only step the US took after the lend-lease was taking over Iceland, - so they extended their perimeter. The first proper contact between Germany and the US occured in the N-Atlantic where a US destroyer was torpedoed. That was 1941, but before Pearl Harbour.
As to manifest how lulling the US were, they were totally unprepared for the naval warfare so at the entry, - into 1942, the German subs had a party while sinking US ships.
That is close to 3 years from Britain and France recognizing Hitler as a threat.
Then here:
"B) In 1938, the United States was a bit player on the world stage with a weak, poorly-equipped and trained military, flat broke and little respected."
Yet, playing boss on the Japs and by no means bankrupt compared to the French and British. After all, as well, the US is a much bigger nation than the other put together. FYI, Britain was about bankrupt and running on food rationing before the fulfillment of the lend-lease.
As for the Scope of commitment - well, when the US gets rolling it's unstoppable

That meant in the positive way. When the US gets serious it's serious. But it took them one heck of a time to figure it's enemies at the time.
Give France it's chance, - if France gets really serious dealing with Muslim extremists, it's one heck of an ally.