ect to regulation by the states and therefore prima facie immune," 938 F. 2d, at 928, appears to rest on the entity-based analysis we have rejected. As with the foreign reinsurers, we express no opinion whether the activities of the domestic reinsurers were "regulated by State Law" and leave that question to the Court of Appeals on remand.
[13]  Petitioners correctly concede this point. See Brief for Petitioners in No. 91-1111, p. 32, n. 14.
[14]  As we have noted before, see Group Life & Health Ins. Co. v. Royal Drug Co., 440 U. S. 205, 217 (1979); SEC v. National Securities, Inc., 393 U. S. 453, 458 (1969), the McCarran-Ferguson Act was precipitated by our holding in South-Eastern Underwriters that the business of insurance was interstate commerce and thus subject generally to federal regulation under the Commerce Clause, and to scrutiny under the Sherman Act specifically. Congress responded, both to "ensure that the States would continue to have the ability to tax and regulate the business of insurance," Royal Drug Co., 440 U. S., at 217-218 (footnote omitted), and to limit the application of the antitrust laws to the insurance industry, id., at 218. In drafting the ง 3(b) exception to the ง 2(b) grant of antitrust immunity, Congress borrowed language from our description of the indictment in SouthEastern Underwriters as charging that "[t]he conspirators not only fixed premium rates and agents' commissions, but employed boycotts together with other types of coercion and intimidation to force nonmember insurance companies into the conspiracies." 322 U. S., at 535.
[15]  Section 2 of the Sherman Act, 26 Stat. 209, as amended, 15 U. S. C. ง 2, prohibits monopolization of, or attempts or conspiracies to monopolize, "any part of the trade or commerce among the several States, or with foreign nations."
[16]  The majority claims that this refusal to deal was a boycott only because "membership in the association [had] no discernible bearing upon the terms of the refused reinsurance contracts." Post, at 809. Test