For the record, the US entered WW2 after more than four years of fighting- Japan was the proximate cause of US entry, and they had been engaged in their horrify

For the record, the US entered WW2 after more than four years of fighting- Japan was the proximate cause of US entry, and they had been engaged in their horrifying, semi-demi-hemi genocidal war in China since the Marco Polo bridge incident of 1937, two years before Hitler stared anything serious in Europe. I suspect the authors point is that most countries in Central America were original members of the United Nations (signing the declaration in January 1942) and Brazil, Bolivia, Colombia, Chile, Paraguay, Peru, Ecuador, Uruguay and Venezuela all joined the war between 1943-5. Argentina was the last country in South America to join the war, at the end of March 1945- Hitler survived little more than a month of war with Argentina. And for those countries, it largely was about pressure from the US.