The locus of world opinion is the United Nations General Assembly or UNGA, where all members of the United Nations are represented. A resolution approved by the UNGA, even when not legally binding, is the expression of world opinion. A state that is rebuffed in the Security Council because of the veto of one of the five permanent members can bring the issue to the UNGA. World opinion matters because a state does not want to be an outcast in the civilized community of nations.
In 1986, when the US refused to comply with an adverse ruling of the International Court of Justice (ICJ) in the Nicaragua v. US case, Nicaragua asked the Security Council to approve a resolution calling for the US to comply with the ruling. The US, a permanent member of the Security Council, promptly vetoed the resolution. Nicaragua then sponsored a resolution in the UNGA demanding that the US comply with the ruling. The resolution passed overwhelmingly, 94 to 3. The following year, Nicaragua again sponsored the same resolution, and this time, only Israel joined the US against the resolution. The US suffered a huge reputational cost as the US appeared like a rogue state. World opinion eventually forced the US, the greatest economic and military power in the world, to strike a face-saving compromise with Nicaragua that effectively complied with the ICJ ruling.
Nicaragua was alone in fighting the US, which violated the territorial integrity of Nicaragua by mining its territorial seas and supplying arms to the Contra rebels. Yet Nicaragua won the support of the world because the ICJ ruling represented the rule of law. The Philippines not only has its Unclos arbitral ruling in its favor, it also has the support of four Asean coastal states — Vietnam, Malaysia, Indonesia, and Brunei — whose exclusive economic zones (EEZs) are encroached by the same nine-dash line of China that encroaches on Philippine EEZ. These four Asean coastal states are expected to support the Philippines if it sponsors a resolution in the UNGA calling for China to comply with the ruling in the South China Sea Arbitration.
Before and after the issuance of the arbitral ruling, the G7 countries declared that the Philippines and China must comply with the arbitral ruling. The countries that regularly conduct freedom of navigation and overflight operations in the South China Sea — the US, UK, France, Japan, Australia, Canada, and India — have either expressly or impliedly used the arbitral ruling to justify their naval and aerial operations in the South China Sea. All these countries will certainly support the Philippines in the UNGA.
The small coastal states that depend on Unclos to protect their maritime zones will logically also support the Philippines in the UNGA. In 2016, tiny Timor Leste brought Australia before an Unclos compulsory conciliation commission to seek a more equitable delineation of its overlapping maritime zones with Australia. In 2018, Australia and Timor Leste reached a compromise settlement based on the proposal of the conciliation commission. Timor Leste and other small coastal states know that Unclos protects their maritime zones, and it is in their paramount national interest to uphold Unclos.
Most of the 27 European Union states took that position that China and the Philippines must comply with the arbitral ruling. Among the three states that were lukewarm — Greece, Hungary, and Croatia—Greece presents a lesson to other states. Greece was more interested in courting China to invest in the Port of Piraeus than in upholding Unclos. However, Greece today is fervently invoking Unclos to prevent Turkey from encroaching on the EEZs of its tiny habitable islands in the Aegean Sea.
The dispute in the Aegean Sea should be resolved in accordance with customary international law. Turkey has not ratified Unclos, but the Unclos provisions on the EEZ are now part of customary international law binding on Turkey. The aim of Turkey is an “equitable solution” to the overlapping EEZs in the Aegean Sea. Unclos has an “equitable solution” principle that will benefit Turkey, a principle that has benefited Myanmar in its arbitration with Bangladesh, and Nicaragua in its arbitration with Colombia. In the UNGA, most member states will obviously vote to uphold Unclos, which is the paramount national interest of almost all coastal states.