The Supreme Court in its last term by a vote of 6-3 invalidated a statute passed by Congress touching on the status of Jerusalem, affirming the U.S. Court of Appeals for the D.C. Circuit decision in Zivotofsky v. Secretary of State that the President's power to recognise foreign sovereigns is exclusive and trumps Congress's authority to regulate passports. The Court's decision in Zivotofsky v. Kerry (Zivotofsky II) represents the first time the Court has struck down a congressionally enacted law on the basis of a separation-of-powers infringement involving a matter of foreign affairs. At the same time, the Court rejected the executive branch assertion that it has exclusive authority to conduct international diplomacy, while endorsing Congress's ample authority to influence the nation's foreign affairs. The implications the decision will have on Congress's foreign affairs authority will likely depend on its interpretation by lower courts, as well as the two political branches. This book briefly describes legislative efforts to modify U.S. policy with respect to Jerusalem, in particular multiple enactments of the passport provision. The book next summarises the appellate court's opinion finding the passport measure at issue unconstitutional. Turning to the Supreme Court decision, it presents brief synopses of the petitioner's argument, the Secretary of State's brief in response, and briefs of amici curiae submitted by the Senate and by some Members of the House of Representatives. The book then summarises the Supreme Court decision, including concurrences and dissents. Finally, the book concludes by suggesting possible implications of the decision with respect to Congress's authority to influence foreign affairs.