What are some reasons why the US should have intervened earlier during World War 2?

In response to this question I am deliberately going to try not to be offensive to the people in the US that read these pages. I don't want to be ungrateful to the fact that had it not been for the support of the US & its people the difficulties that Britain endured during WW2 would have been even more severe. Lend/Lease was crucial to Britain & it was when the US was a Neutral power. Much was done behind the scenes which we know nothing of even now. What would have happened had not Japan attacked Pearl Harbor I do not know, would the US have stayed neutral indefinately, I think not. I cannot really say what took the US as long as it did to aviod war against the Nazis, I'm just grateful they turned up when they did. And if you think I avoided answering the question well I guess you are right....