Raul Gallegoss article on a bilingual America (You better get used to living in a bilingual America, May 17, Page B1) suggests that German, Italian and Polish immigrants to the U.S. had to learn English because their country of origin did not share a border with their adopted country, and that America does share a border with Mexico, gateway to a whole continent of Spanish speakers. Therefore, he says we need to be Spanish bilingual. He seems not to hold that those on the southern side of that same border need for any reason to learn some English.
I know some Spanish and am glad of it. I would not expect residents south of the border to accommodate me in English, though I have experienced its use in some non-English European countries.
Spanish is spreading in the U.S., but English is spreading worldwide. Commercial airline pilots anywhere can only talk to control towers in English.
Young children learn languages easily.