Non-US profits are generally taxed only if the cash is repatriated back into the United States. So, for example, Coca-Cola's profits that it generates in countries outside the United States are not taxed by the IRS until that cash is moved into an account that is domiciled in the US. Of course, this gets very complicated very quickly, isn't necessarily appropriate for an early-stage startup, and is the kind of thing for which you need to have accountants and tax attorneys on retainer or in-house to properly advise you.