re Why US entered the war in Europe

The reason why the US entered the war in Europe in simple, and that is that Hitler declared on the US just after Pearl Harbour and that gave Churchill, who was half American, the chance to persuade Roosevelt to commit forces to the European theatre.

I think that's a bit naive. The conflict between the US and Japan had

been smouldering since at least 1937, and any time up until Pearl Harbor it was still amenable to a diplomatic solution. The fact that no diplomatic solution was achieved is largely due to the fact that FDR was a staunch republican (small 'r' and saw America's manifest destiny as being to topple monarchies and break up colonial empires wherever they

existed. US involvement in the ETO prior to Pearl Harbor was part of this grand design of Roosevelt's, in that he believed that by helping the weaker nations in the European struggle, he could ensure a protracted contest that would ultimately weaken all the nations of Europe to the point where, once it was all over and done with, they would no longer have the strength to maintain their overseas colonies.

He was right.

Nope.

and that is

Hitler declared war partly because of major violations of the duties of neutrals by the US, and partly because the US Navy was already in a shooting war with him. Moreover, Hitler's comment (something like 'a great nation declares war, and is not declared war on' suggests that he thought that a US declaration of war was likely soon.

and that gave While Churchill was a superb orator, and very persuasive at times, it is easy to find lots of cases in which he failed to influence US policy. The reason US forces were committed en masse to fight Germany, rather than the more immediately popular war against Japan (who, after all, was the sneak attacker), was Roosevelt's strategic decision.

It is naive when considering US foreign policy in 1938-41 to ignore the potential military, economic and political consequences for the US of a single authoritarian aggressive European super-state.

In terms of Mr Lusby's actual remark, the US assisted the UK, the mother country of the British Commonwealth and Empire, which was a stronger power than both the European aggressors put together, although temporarily militarily weaker due to 20 years of neglect of the armed forces.