Resident aliens in the United States are taxed on their world wide income. Nonresident aliens are taxed on their U.S source income.
Code Section 7701(b)(1)(A)
An alien will be considered...
Code Section 7701 (a)(30)
U.S citizens are U.S Persons and Citizens of foreign countries are U.S Persons who meet either of the following two tests:
Green Card test
Substantial...