Ah, yes, the secret mind-altering chemicals that make the funny little foreign people bend to America's will.
Yeah you have a point. I don't think its right to ask them for the cola recipe. What might be better is to make them sign bonds that there is no toxic additives in their syrup and an undertaking that they can be fined a few billion dollars even if a single genuine bottle of coke/pepsi/any other drink is found to contain toxic substances over permissible limits. Periodic testing of random samples by NGOs and gvernment agencies will be able to solve the problem.