the US govt only has financial domain over US dollars
expecting to collect taxes off transactions in other currencies is absurd. the US govt only comes into play once the currency changes to US dollars.
they might as well push for all transactions conducted in euros. which is stupid.
Nice try. A capital gain is a capital gain, and they have jurisdiction over everyone claiming citizenship.
Anyone who does business in multiple countries calculates and pays taxes in different currencies all the time. As a U.S. taxpayer, I have to report my foreign income and capital gains on my U.S. tax return. If I buy an investment property in Europe and sell it five years later, I have to report the capital gain on my U.S. tax return even if both transactions are conducted in euros. I simply document the purchase price and the sale price on my U.S. return based on the euro-dollar exchange rates at the time of purchase and the time of sale.