8 JAM v. INTERNATIONAL FINANCE CORP. BREYER, J., dissenting many organizations contracted in scope in 1952, when the State Department modified foreign government immunity to exclude commercial activities. Most organizations could not rely on the treaty provisions quoted above to supply the necessary immunity. That is because, unless the treaty provision granting immunity is “self-executing,” 1.e., automatically applicable, the immunity will not be effec- tive in U.S. courts until Congress enacts additional legis- lation to implement it. See Medellin v. Texas, 552 U.S. 491, 504-505 (2008); but see id., at 546-547 (BREYER, J., dissenting). And many treaties are not self-executing. Thus, in the ordinary case, not even a treaty can guaran- tee immunity in cases arising from commercial activities. The UN provides a good example. As noted, the UN Charter required the United States to grant the UN all “necessary” immunities, but it was not self-executing. In 1946, the UN made clear that it needed absolute immu- nity from suit, including in lawsuits based upon its commer- cial activities. See Convention on Privileges and Immuni- ties of the United Nations, Art. II, §2, Feb. 18, 1946, 21 U.S. T. 1422, T. I. A. S. No. 6900 (entered into force Apr. 29, 1970); see also App. to S. Exee. Rep. No. 91-17, p. 14 (1970) “The U. N.’s immunity from legal process extends to matters arising out its commercial dealings ...”). But, until Congress ratified that comprehensive immunity provision in 1970, no U.S. law provided that immunity but for the Immunities Act. Jd., at 1. Both the UN and the United States found this circumstance satisfactory because they apparently assumed the Immunities Act extended immunity in cases involving both commercial and noncommercial activities: When Congress eventually (in 1970) ratified the UN’s comprehensive immunity pro- vision, the Senate reported that the long delay in ratifica- tion “appears to have been the result of the executive branch being conten