Question III, Political Law, 2017 Bar Exam

State A and State B, two sovereign states, enter into a 10-year mutual defense treaty. After five years, State A finds that the more progressive State B did not go to the aid of State A when it was threatened by its strong neighbor State C. State B reasoned that it had to be prudent and deliberate in reacting to State C because of their existing trade treaties.

(a) May State A now unilaterally withdraw from its mutual defense treaty with State B? Explain your answer. (2.5%)

(b) What is the difference between the principles of pacta sunt servanda and rebus sic stantibus in international law? (2.5%)

(c) Are the principles of pacta sunt servanda and rebus sic stantibus relevant in the treaty relations between State A and State B? What about in the treaty relations between State B and State C? Explain your answer. (2.5%)

Suggested Answer:

(a) No. Answer

Under the 1969 Vienna Convention on the Law of Treaties, a material breach of a bilateral treaty by one of the parties entitles the other to invoke the breach as a ground for terminating the treaty or suspending its operation in whole or in part. Rule

In the case at bar, State C only made threats against State A. No international armed conflict began that could trigger the mutual defense treaty compelling State B to defend State A against State C. Accordingly, State B did not commit material breach. Apply

Thus, State A may not unilaterally withdraw from the mutual defense treaty. Conclusion

(b) Under in...