International Law Practice Exam Questions

1. 1.Pacta sunt servanda: Under Article 26 of the Vienna Convention on the Law of Treaties, every treaty in force is binding and must be performed in good faith. Country A is obligated to comply unless a valid exception applies.
2. 2.Rebus sic stantibus (fundamental change of circumstances): Under Article 62 of the Vienna Convention, a fundamental change of circumstances may be invoked to terminate or withdraw from a treaty only if (1) the circumstances were an essential basis for consent, (2) the change was not foreseen, and (3) the change fundamentally transforms obligations. Security threats are generally not sufficient.
3. 3.Withdrawal provisions: Country A must follow the treaty's withdrawal procedures (12 months' notice). Manufacturing weapons before formal withdrawal is a breach of the treaty.
4. 4.State responsibility: Country A's breach gives rise to state responsibility under the Articles on State Responsibility. Other state parties may invoke countermeasures or seek remedies through treaty dispute resolution mechanisms.

1. 1.Transboundary harm: Under the Trail Smelter principle, a state is responsible for ensuring activities within its territory do not cause significant harm to other states. Country C has an obligation to prevent transboundary pollution.
2. 2.State responsibility: Country C may be responsible for failing to regulate the corporation's activities. The state's duty is one of due diligence in preventing harm, not strict liability.
3. 3.Direct corporate liability: International law traditionally applies to states, not corporations. However, the UN Guiding Principles on Business and Human Rights establish a framework for corporate responsibility to respect human rights.
4. 4.Country D's remedies: Diplomatic protest, negotiation, international arbitration, or proceedings before the International Court of Justice (if jurisdiction exists). The polluter-pays principle may apply.

Correct Answer: B

Under Article 56 of the Vienna Convention on the Law of Treaties, a treaty containing no withdrawal clause may not be denounced unless (a) it can be established that the parties intended to allow withdrawal, or (b) the right of withdrawal can be implied by the nature of the treaty. If withdrawal is permitted under either exception, 12 months' notice is required.

Correct Answer: C

Article 2(4) of the UN Charter prohibits the use of force against the territorial integrity of any state. Self-defense under Article 51 requires an armed attack (or, under the anticipatory self-defense doctrine, an imminent armed attack). The burden is on Country X to demonstrate that the use of force was a proportionate and necessary response to an imminent threat. Without meeting these criteria, the military incursion violates international law.

Correct Answer: C

Under the Charming Betsy canon (from Murray v. Schooner Charming Betsy), courts should interpret domestic statutes to be consistent with international law when possible. This avoids conflicts between domestic and international obligations. If a genuine conflict exists, most domestic systems give priority to later-in-time domestic legislation, but courts first attempt harmonious interpretation.