the US entered the Second World War because the US ruling ELITE was Anglophile.

The chief beneficiaries of the American war effort were the elite. During the war, the government awarded almost all military production contracts to large corporations. Although unions cooperated with the government and pledged not to strike, many non-unionized workers went on strike during the war years—indeed, there were more strikes during the World War Two years than in “any comparable period in American history.”
War benefitted the American elite by providing businesses with lucrative contracts for cars, guns, and planes. In response to the growing power of the Establishment, American unions—according to Zinn, many of them, though he doesn’t provide exact numbers—protested against American capitalism.

It was a war waged by a goverment whose chief beneficiary despite volumes of reforms-was a wealthy elite
The alliance between big business and the goverment went back to the very first proposals of Alexander Hamilton to Congress after the revolutionary war. by the deression, Roosevelt had once denounced the economic royalists but he always had the support of certain important business leaders. during the war , as Bruce Catton saw it from his post in the war production board
The economic royalists denounced and derided/had a part to play now

reference : people's histody of America, Howard Zinn