BY SAUL HOFILEÑA JR.
DEC 24, 2022
IN LEGAL TERMS
PACTA sunt servanda is a brocard which in English means "agreements must be kept." It is a maxim or rule which states that the provisions of treaties should be honored, that "every treaty in force is binding upon the parties to it and must be performed by them in good faith." The principle enshrined in the Vienna Convention on the Law of Treaties (VCLT) to which the Philippines is a signatory stipulates that parties should adhere to their treaty obligations and must also comply in good faith with the terms of the treaty. The principle of pacta sunt servanda is the reason why compliance to treaty obligations is mandatory.
As a rule, a State cannot invoke the provisions of its internal laws to justify non-observance of a treaty, or breaking faith. A treaty shall bind all the territories of a signatory country unless a reservation is made which renders the treaty not applicable to a portion of the territory of the contracting State. It is an essential principle of the Law of Nations, according to the Declaration of London of 1871, "that no power can liberate itself from the engagements of a treaty nor modify the stipulations thereof, unless with the consent of the contracting parties, by means of an amicable understanding."
Treaties should be kept sacred, that is the reason for the rule of pacta sunt servanda. A State that refuses to honor its treaty obligations cannot occupy a rightful place in the community of nations. However, the principle of rebus sic stantibus adds strain to the doctrine of pacta sunt servanda.
Rebus sic stantibus is Latin for "as long as things remain the same." Although treaties must be kept in good faith, customary international law and the VCLT have recognized the reality that States may sometimes be relieved, in whole or in part, of their treaty obligations under very exceptional circumstances.
Although the provisions of the VCLT which pertain to the rebus sic stantibus doctrine do not allow a party to renege on a treaty even if there has been a fundamental change of circumstances not foreseen by the parties, there are two exceptions to the rule: (a) the existence of those circumstances constituted an essential basis of the consent of the parties to be bound by the treaty; and (b) the effect of the change radically transforms the extent of obligations still to be performed under the treaty.
It is clear that absent the two conditions taken in conjunction with the "fundamental change of circumstances even if not foreseen by the parties," rebus sic stantibus may not be used as a basis to terminate a treaty or to withdraw therefrom. There is no clear rule on when this doctrine may be invoked. It appears that if rebus sic stantibus is indeed invoked, the existence of the conditions that justify its application may be determined by the parties themselves, or by a third party, such as the World Court. The body of the treaty itself may clearly specify in minute detail when the doctrine may be invoked. However, rebus sic stantibus should be used with great caution because it goes against the obligatory nature of treaties. Moreover, the determination that conditions exist to justify the breach of a treaty is oftentimes subject to perception, politics, existing need and nationalism.
Rebus sic stantibus may not be invoked if land or maritime boundaries between States are established by the treaty. This is to prevent conflicts between States resulting from the refusal of one signatory State to honor land or sea boundaries established and identified in a treaty because of change in circumstances.
The VCLT also prohibits a party guilty of a breach which resulted in the "change in circumstances," to invoke rebus sic stantibus for the reason that a State responsible for the circumstances that gave rise to the causes for the abrogation of the treaty should not be allowed to profit from the change of circumstances brought about by its fault or actions by withdrawing from its treaty obligation.
In the Gabčíkovo-Nagymaros Project, which was resolved by the International Court of Justice (ICJ) in 1997, an international treaty was signed by Hungary and the former Czechoslovakia (now the Czech Republic and Slovakia) to build a dam to generate hydro-electric energy. Hungary stopped work on the project in 1989 and 1993. In the case filed before the ICJ, it cited changes in the political systems of the two signatory States to justify work stoppage. Hungary invoked rebus sic stantibus. Could Hungary justifiably break faith?
The ICJ overruled Hungary because its main justification for suspending work was the change of its socialist economic system to a capitalist one. It was not reason enough to "break faith" with a treaty on the basis of rebus sic stantibus.