suppose you are a dual national living in the uk and working there. you earn 100k per year and pay uk taxes. under us tax law you can exclude all of that income and pay $0 taxes on it. you just have to file a tax return saying you earned it and paid uk taxes on it at a tax rate higher or equal to the us rate at that bracket. same story for france, but their bar is 50% of france's tax rate.
United States