Magallona vs. Ermita

Factual Background

The petition challenged the constitutionality of RA 9522, which amended the baselines law that had been first enacted as RA 3046 in 1961 and later corrected by RA 5446 in 1968. RA 9522 adjusted certain basepoints, shortened one baseline to comply with UNCLOS III limits, and classified the Kalayaan Island Group (KIG) and Scarborough Shoal as areas to be treated as a regime of islands under Article 121 of UNCLOS III. Petitioners alleged that RA 9522 reduced Philippine maritime territory, undermined sovereignty and national security, and prejudiced subsistence fishermen.

Legislative Antecedents and International Context

The Court recited the legislative and treaty background leading to RA 9522. RA 3046 originally demarcated Philippine baselines after UNCLOS I and before UNCLOS III. The Philippines ratified UNCLOS III, which prescribes the method and limits for drawing archipelagic baselines and sets measurement points for maritime zones and the continental shelf. UNCLOS III therefore created a framework within which archipelagic States must specify basepoints and baselines to mark the starting points for measuring territorial sea, contiguous zone, exclusive economic zone, and continental shelf.

Petitioners’ Principal Contentions

Petitioners asserted two principal constitutional defects. First, they contended that RA 9522 effectuated a diminution of Philippine territory and thus violated Article I, Section 1, 1987 Constitution, as that constitutional definition embodied the territorial description of the Treaty of Paris and related instruments. Second, petitioners argued that RA 9522 opened waters landward of baselines to passage by foreign ships and aircraft, thereby compromising sovereignty, endangering national security and environment, and contravening constitutional policies such as the nuclear‑free policy and provisions protecting marine resources and subsistence fishermen.

Respondents’ Principal Defenses

Respondents defended RA 9522 as necessary to comply with UNCLOS III and to enable the Philippines to delineate with precision its baselines and maritime zones, including its claim to an extended continental shelf. They denied that RA 9522 surrendered territory or weakened Philippine sovereignty over the KIG, Scarborough Shoal, or Sabah. Respondents argued that UNCLOS III governs sea‑use rights and maritime delimitations rather than the acquisition or loss of land territory.

Procedural Posture and Issues Framed

The action was an original petition for the writs of certiorari and prohibition brought by petitioners before the Supreme Court, En Banc. The threshold issues the Court framed were whether petitioners had locus standi and whether the writs of certiorari and prohibition were proper remedies to test the constitutionality of RA 9522. The substantive issue was whether RA 9522 was unconstitutional for the reasons alleged.

Threshold Rulings on Standing and Remedy

The Court held that petitioners had locus standi as citizens presenting a constitutionally sufficient interest in issues of national importance, noting the peculiar nature of RA 9522 and the difficulty of finding more direct litigants. The Court also held that the writs of certiorari and prohibition have historically been viewed as proper remedial vehicles for testing the constitutionality of statutes and other acts of government when issues of constitutional import are presented.

Merits — Characterization of RA 9522 and Role of UNCLOS III

On the merits, the Court reasoned that UNCLOS III regulates sea‑use rights and delimits maritime zones and continental shelves, but it does not govern the acquisition or cession of land territory. Baselines legislation such as RA 9522 is a statutory mechanism to identify basepoints and draw baselines in conformity with UNCLOS III so that coastal and archipelagic States can measure the breadth of maritime zones from those baselines. The Court therefore rejected the petitioners’ premise that an UNCLOS‑compliant baselines law can, by itself, diminish the Philippines’ territorial sovereignty as defined by the Constitution and historical treaties.

Merits — Treatment of the KIG and Scarborough Shoal

The Court addressed petitioners’ contention that RA 9522’s exclusion of the KIG and Scarborough Shoal from archipelagic baselines weakened the Philippines’ claim and resulted in the loss of substantial territorial waters. The Court found that RA 9522 in fact left those features outside the archipelagic baselines as RA 3046 had done, except that RA 9522 optimized basepoints and shortened an overlong baseline to comply with UNCLOS III. RA 9522 expressly reaffirmed the Philippines’ claim over the KIG and Scarborough Shoal by designating them as areas to be treated as a "Regime of Islands" under Article 121 of UNCLOS III (Section 2 of RA 9522). The Court explained that enclosing those outlying features within straight baselines drawn to include them would have breached UNCLOS III constraints — notably that baselines must not depart appreciably from the general configuration of the archipelago and that baseline lengths are subject to numerical limits. The Court therefore concluded that classification as a regime of islands complied with international law while preserving Philippine sovereignty and jurisdiction.

Merits — Sabah and RA 5446

The Court rejected petitioners’ claim that RA 9522 implicitly abandoned the statutory claim over Sabah. It noted that Section 2 of RA 5446, which states that the baselines definition is without prejudice to delineation of baselines around Sabah, remained unrepealed. The Court further observed that RA 9522’s Section 3 expressly affirmed Philippine dominion, sovereignty, and jurisdiction over all portions of the national territory as defined in the Constitution and applicable laws. The Court therefore found no basis to conclude that RA 9522 relinquished any claim over Sabah.

Merits — Internal Waters, Passage Rights, and Constitutional Policies

The Court addressed petitioners’ concern that RA 9522 converted internal waters into waters subject to international passage rights that would undermine the Constitution’s nuclear‑free policy and environmental guarantees. The Court explained that whether described as “internal waters” under Article I, Section 1, 1987 Constitution or as “archipelagic waters” under UNCLOS III, the Philippines exercises sovereignty over waters landward of baselines, including airspace and subsoil. The Court acknowledged that UNCLOS III recognizes constrained freedoms such as the right of innocent passage and archipelagic sea lanes passage but emphasized that those rights do not negate sovereignty. The political branches retain authority to designate routes, regulate passage, suspend innocent passage temporarily for security, and adopt legislation to safeguard national interests. The Court also observed that provisions of Article II cited by petitioners are non‑self‑executing legislative guides and do not, without implementing facts or legislation, yield judicially enforceable constitutional rights in this context.

Quantitative Effect on Maritime Zones

Relying on figures submitted by respondents, the Court noted that RA 9522 increased the Philippines’ total maritime space — including internal waters, territorial sea, and exclusive economic zone — by 145,216 square nautical mile