Q: If in a case, the Supreme Court announce that an int. treaty is inconsistent with the Constitution, what will happen?

A: Nations generally review treaties before becoming signatories. That's when they have the opportunity to determine if a proposed treaty has provisions that are contrary to its constitution. Good luck

A: It depends on the particular facts and circumstances and whether the treaty is self-executing or not.

In Medellin v Texas, the Supreme Court determined that a treaty between the United States and Mexico pertaining to Mexican nationals charged with crimes in the United States did not require the State of Texas to follow the treaty in a death sentence case against a Mexican national convicted of capital murder in light of constitutional constraints on the power of the federal government to infringe on the sovereignty of the State of Texas.

A: If the Supreme Court determines that an international treaty is inconsistent with the Constitution, the legal effect of such a pronouncement would generally mean that the provisions of the treaty in question cannot be applied in a manner that contravenes the Constitution. In such scenarios, the treaty cannot be given effect to the extent of its inconsistency with the Constitution. The ruling will hold a binding effect and will not be limited to the parties in the case; it will have a broader applicatory scope, influencing how the treaty is implemented nationwide.

Following such a ruling, the government might take steps to amend the domestic laws to ensure compliance with the constitutional provisions upheld by the Supreme Court. The government may, theoretically, also opt to renegotiate the terms of the treaty with the concerned international parties to remove the inconsistencies, or in extreme cases, decide to withdraw from the treaty altogether, depending on the gravity of the inconsistency and its implications on the nation’s interests.

As for historical examples, cases where the Supreme Court has outright declared an international treaty as unconstitutional are extremely rare. Generally, courts tend to interpret international treaties in a manner that is consistent with the Constitution to avoid conflicts between domestic and international law. However, it is not unprecedented for legal debates to arise concerning the constitutionality of international agreements.

A meticulous review of case law might provide you with specific cases, though I would recommend focusing on notable Supreme Court decisions that scrutinize international agreements vis-à-vis constitutional provisions for a detailed understanding of this matter.

Best regards and good luck with your research.