In Japan Line, Ltd. v. County of Los Angeles, 441 U.S. 434, 60 L. Ed. 2d 336, 99 S. Ct. 1813 (1979), the United States Supreme Court articulated a test for determining whether a state regulation affecting foreign commerce violates the Commerce Clause. As a basis for the standard, the Court borrowed the four-prong test set forth in Complete Auto Transit, Inc. v. Brady, 430 U.S. 274, 51 L. Ed. 2d 326, 97 S. Ct. 1076 (1977), for determining the constitutionality of state taxation that affects interstate commerce. The decision in Complete Auto provided that if the state tax "is applied to an activity with a substantial nexus with the taxing State, is fairly apportioned, does not discriminate against interstate commerce, and is fairly related to the services provided by the State," no impermissible burden on interstate commerce exists. Id. at 279. The Court in Japan Line articulated two additional factors for consideration of taxes assessed against instrumentalities engaged in foreign commerce, which include "whether the tax, notwithstanding apportionment, creates a substantial risk of international multiple taxation, and, second, whether the tax prevents the Federal Government from 'speaking with one voice when regulating commercial relations with foreign governments.'" Japan Line, 441 U.S. at 451 (quoting Michelin Tire Corp. v. Wages, 423 U.S. 276, 285, 46 L. Ed. 2d 495, 96 S. Ct. 535 (1976)). The Supreme Court subsequently clarified this prong of the test, determining that "a state tax at variance with federal policy will violate the 'one voice' standard if it either implicates foreign policy issues which must be left to the Federal Government or violates a clear federal directive." Container Corp. of Am. v. Franchise Tax Bd., 463 U.S. 159, 194, 77 L. Ed. 2d 545, 103 S. Ct. 2933 (1983).