I disagree, as a native speaker of a language where "bilion" means 10^12, it's clear to me that "billion" means 10^9 when used in English text. So I disagree that is ambiguous. But maybe that's wiem that way to make sure foreigners with poor understanding of English don't read it incorrectly, because I guess it gets confusing (even journalists sometimes make a mistake of translating that wrong).
"Billion" meant 10^12 in England until... some time in the 1950s, I think? But 10^9 in the USA.
So there was confusion, even in the English-speaking world. Was. If I understand correctly, England has adopted 10^9, and so now there is no ambiguity.
