Well, up here it's two, and it seems to work fine. Of course, here you have a very centred French-speaking population (Quebec, New Brunswick, and pockets in Manitoba and Ottawa), so it's a bit easier to centralise. Comes from the fact that we are really two separate nations (not countries!) within the same country. BTW, I learned last week that a nation is simply a group of people ethnically and historically united in one mass. It's pretty much only English that takes nationalism to mean countries.
I don't think it really makes any sense for the US to get a second language. I mean, what would you do? Spanish hardly seems appropriate in Montana, French is useless outside Louisiana, for the most part, and the only other tongue that would be logical, some form of Native American, is really disjointed (by which I mean varies largely according to local dialect...obviously Navajo is different than Inuit.)
I would consider that you should probably learn to adapt to English in the US. I mean seriously, not to sound prejudiced against any language, but it's a skill you need to live a productive and happy life in any country (I mean the primary language, not necessarily English.)
I don't think Americans are against learning a second language, though certainly the public schools aren't mandated in any way (up here, you have a
right to be able to access French immersion schools.) It's still a valuable skill. I mean, try making business deals in Beijing in English, for example.
Just my 2 cents' worth...
