Core Legal Answer & Context: "Pacta Tertiis Nec Nocent Nec Prosunt" is a fundamental maxim of treaty law, meaning "agreements neither harm nor benefit third parties." This principle, also known as res inter alios acta, asserts that a treaty creates rights and obligations only for the states that are parties to it. It cannot impose obligations on a non-party state without its express consent, nor can it confer rights upon a non-party state without its assent.

Relevant Statutes and Sections:

1. Vienna Convention on the Law of Treaties (VCLT), 1969:
   • Article 34 (General rule regarding third States): Explicitly states: "A treaty does not create either obligations or rights for a third State without its consent."
   • Article 35 (Treaties providing for obligations for third States): Requires express written consent for an obligation to arise for a third state.
   • Article 36 (Treaties providing for rights for third States): Presumes assent for a right to arise for a third state, unless the contrary is indicated.

Important Landmark Cases:

1. Free Zones of Upper Savoy and the District of Gex Case (France v. Switzerland, PCIJ, 1932): The Permanent Court of International Justice (PCIJ) affirmed that a treaty cannot create rights or obligations for a third state without its consent. The Court examined whether certain treaties created rights for Switzerland, a non-party, and concluded that they could only do so with Switzerland's assent, thereby upholding the maxim.
2. Island of Palmas Case (Netherlands v. United States, 1928): While not directly about pacta tertiis, the arbitrator's reasoning implicitly supports the idea that agreements between two states cannot automatically bind a third state regarding territorial claims without its involvement or consent, reinforcing the consensual nature of international obligations.

Clear Conclusion: The maxim Pacta Tertiis Nec Nocent Nec Prosunt is a cornerstone of treaty law, upholding state sovereignty and the consensual nature of international obligations. While the VCLT provides mechanisms for third states to accept obligations or rights, the fundamental principle remains that treaties are binding only on their parties, ensuring that states are not involuntarily subjected to external legal regimes.