If you have a customer in the USA, you wouldn't necessarily expect to have to pay taxes in the USA, unless you have a business base there. What counts as a base looks like changing, which will mean counting things that didn't previously count, if OECD proposals are adopted.
Controversy over OECD changes to permanent establishment rules Multinational corporations are opposing new international proposals that would lower the threshold for finding that a company has a permanent establishment in a particular jurisdiction. The proposals are part of the Organization for Economic Development and Cooperation's Base Erosion and Profit Shifting (BEPS) project, aimed at preventing arbitrage-based tax-planning schemes used by multinational companies. Many such schemes attempt to avoid having a permanent establishment (PE) in countries where the company generates significant revenues, thus avoiding corporation taxes in those jurisdictions.