((a)) ** In general** The tax imposed by section 2101 shall be credited with the amounts determined in accordance with sections 2012 and 2013 (relating to gift tax and tax on prior transfers).
((b)) ** Unified credit**
((1)) ** In general** A credit of $13,000 shall be allowed against the tax imposed by section 2101.
((2)) ** Residents of possessions of the United States** In the case of a decedent who is considered to be a “nonresident not a citizen of the United States” under section 2209, the credit under this subsection shall be the greater of—
((A)) $13,000, or
((B)) that proportion of $46,800 which the value of that part of the decedent’s gross estate which at the time of his death is situated in the United States bears to the value of his entire gross estate wherever situated.
((3)) ** Special rules**
((A)) ** Coordination with treaties** To the extent required under any treaty obligation of the United States, the credit allowed under this subsection shall be equal to the amount which bears the same ratio to the applicable credit amount in effect under section 2010(c) for the calendar year which includes the date of death as the value of the part of the decedent’s gross estate which at the time of his death is situated in the United States bears to the value of his entire gross estate wherever situated. For purposes of the preceding sentence, property shall not be treated as situated in the United States if such property is exempt from the tax imposed by this subchapter under any treaty obligation of the United States.
((B)) ** Coordination with gift tax unified credit** If a credit has been allowed under section 2505 with respect to any gift made by the decedent, each dollar amount contained in paragraph (1) or (2) or subparagraph (A) of this paragraph (whichever applies) shall be reduced by the amount so allowed.
((4)) ** Limitation based on amount of tax** The credit allowed under this subsection shall not exceed the amount of the tax imposed by section 2101.
((5)) ** Application of other credits** For purposes of subsection (a), sections 2012 and 2013 shall be applied as if the credit allowed under this subsection were allowed under section 2010.