SUBJECT: The Concept of ‘The Archipelagic Doctrine’ and the Philippine Baselines Law (RA 9522)

I. Introduction

This memorandum provides an exhaustive analysis of the archipelagic doctrine as a concept in public international law and its manifestation in Philippine domestic law through Republic Act No. 9522, the “Philippine Baselines Law.” The primary objective is to delineate the evolution of the archipelagic doctrine from a unilateral national claim to a recognized regime under the 1982 United Nations Convention on the Law of the Sea (UNCLOS), and to scrutinize how RA 9522 aligns Philippine baselines with this conventional regime. The analysis will cover the historical foundations, legal justifications, specific provisions of RA 9522, and the consequent maritime zones and sovereign rights of the Philippines.

II. Historical Development and Conceptual Foundations of the Archipelagic Doctrine

The archipelagic doctrine is fundamentally a geopolitical and legal concept asserting that an archipelagic state should be considered as a single integrated unit, with its islands and the waters enclosed by straight baselines treated as internal waters subject to its exclusive sovereignty. The Philippines, as an archipelago of over 7,600 islands, was a principal proponent of this concept. Its origins can be traced to domestic legislation: the Treaty of Paris (1898), the Treaty of Washington (1900), and the Convention with Great Britain (1930) defined Philippine territory via “treaty limits” or rectangular lines, creating an implicit claim over the waters within. This was explicitly codified in the 1935 Constitution, which stated, “The Philippines comprises all the territory ceded to the United States by the Treaty of Paris… together with all the islands embraced in the treaty… and all territory over which the present Government of the Philippine Islands exercises jurisdiction.” The archipelagic doctrine was formally articulated and defended internationally by Filipino statesmen and legal scholars, most notably Arturo M. Tolentino, during the First and Second United Nations Conferences on the Law of the Sea (UNCLOS I & II) and culminating in UNCLOS III.

III. The Archipelagic Regime under the 1982 UNCLOS

The persistent advocacy by the Philippines, Indonesia, and other archipelagic states led to the formal recognition of the archipelagic state regime in Part IV of the 1982 United Nations Convention on the Law of the Sea (UNCLOS). Key conventional elements include:

Definition of an Archipelagic State: A state constituted wholly by one or more archipelagos and may include other islands (Article 46).

Drawing of Archipelagic Straight Baselines: Such baselines may be drawn joining the outermost points of the outermost islands and drying reefs, provided the main islands are included and the ratio of water to land within these baselines is between 1:1 and 9:1 (Article 47).

Legal Status of Archipelagic Waters: Waters enclosed by the archipelagic baselines are designated as archipelagic waters, over which the state exercises sovereignty (Article 49). This sovereignty is subject to existing agreements, traditional fishing rights of immediate neighboring states, and the right of innocent passage (Article 52).

Rights of Navigation: The convention establishes the rights of archipelagic sea lanes passage and innocent passage through archipelagic waters (Articles 52-54).

IV. Philippine Baselines Legislation: From RA 3046 to RA 9522

Prior to RA 9522, the governing law was Republic Act No. 3046 (as amended by RA 5446). This law established a system of straight baselines around the Philippine archipelago but also included the “Treaty Limits” or “Philippine Treaty Limits” within its text, creating a persistent ambiguity as to whether the national claim was based on the archipelagic doctrine or on historic title. This ambiguity became a significant legal vulnerability, as the treaty limits were not recognized under customary international law or UNCLOS. RA 9522 was enacted on March 10, 2009, to modernize the baselines system and explicitly align it with UNCLOS, thereby strengthening the Philippines’ legal position under public international law.

V. Key Provisions and Analysis of Republic Act No. 9522 (The Philippine Baselines Law)

RA 9522 redefines the baselines of the Philippine archipelago using two distinct methods:

Archipelagic Baselines for the Main Archipelago: The law establishes a system of 101 straight baselines connecting 101 base points around the outermost islands of the main Philippine archipelago (Section 1). This conforms to Article 47 of UNCLOS, formally claiming the enclosed waters as archipelagic waters.

Regime of Islands for Offshore Territories: For the Kalayaan Island Group (KIG) and Scarborough Shoal (Bajo de Masinloc), the law uses the “Regime of Islands” under Article 121 of UNCLOS. It draws straight baselines around the KIG itself (Section 2) and defines Scarborough Shoal as a regime of islands (Section 3). Crucially, it states that these areas “shall be determined in accordance with Article 121” of UNCLOS, meaning their maritime zones will depend on their status as rocks or islands capable of sustaining human habitation or economic life of their own.

The law contains a seminal saving clause: “The baseline in the following areas over which the Philippines likewise exercises sovereignty and jurisdiction shall be determined as “Regime of Islands” under the Republic of the Philippines consistent with Article 121 of UNCLOS” (Section 2). This clause is critical as it subordinates the national claim to the rules of UNCLOS. Furthermore, Section 4 explicitly states, “The provisions of this Act are without prejudice to the delineation of the continental shelf under Article 76 of UNCLOS.”

VI. Maritime Zones Generated under RA 9522 and UNCLOS

By establishing UNCLOS-compliant archipelagic straight baselines, RA 9522 allows the Philippines to generate the following maritime zones measured from these baselines:

Internal Waters: Waters on the landward side of the baselines (e.g., within bays, rivers).

Archipelagic Waters: The waters enclosed by the archipelagic straight baselines. The Philippines exercises full sovereignty over these waters, subject to the rights of innocent passage and archipelagic sea lanes passage.

Territorial Sea: A belt of sea 12 nautical miles outward from the archipelagic baselines. The Philippines exercises full sovereignty over this zone, subject to the right of innocent passage.

Contiguous Zone: A zone extending 12 nautical miles beyond the territorial sea (24 nm from the baselines), where the Philippines may exercise control to prevent infringement of its customs, fiscal, immigration, or sanitary laws.

Exclusive Economic Zone (EEZ): A zone extending 200 nautical miles from the baselines, where the Philippines has sovereign rights for exploring, exploiting, conserving, and managing natural resources, both living and non-living.

Continental Shelf: The natural prolongation of the Philippine land territory to the outer edge of the continental margin, or to 200 nm from the baselines where the margin does not extend that far. The Philippines has sovereign rights over the resources of the continental shelf.

VII. Comparative Analysis: RA 3046/5446 vs. RA 9522

The following table contrasts the key features of the old and new baselines laws:

Feature	RA 3046 (as amended by RA 5446) – The Old Law	RA 9522 – The New Law
Primary Legal Basis	A hybrid of the archipelagic doctrine and historic claim via the “Philippine Treaty Limits.”	Explicitly the 1982 United Nations Convention on the Law of the Sea (UNCLOS).
Treatment of the Main Archipelago	Used straight baselines, but the reference to treaty limits created ambiguity over the legal status of enclosed waters.	Uses UNCLOS-compliant archipelagic straight baselines (101 segments), clearly establishing the waters as archipelagic waters.
Treatment of the Kalayaan Island Group (KIG) & Scarborough Shoal	Included within the “Treaty Limits” and generally considered part of national territory without a clear maritime regime under international law.	Treats them under the “Regime of Islands” (Article 121, UNCLOS). Their maritime zones are determined by their legal status as islands or rocks.
Compliance with International Law	Problematic; the historic claim to the treaty-limit waters was widely contested and not recognized under conventional or customary international law.	Designed for compliance; adopts the universally recognized UNCLOS framework, strengthening the Philippines’ legal standing.
Clarity on Maritime Zones	Ambiguous, as the treaty limits claim was excessive and not a valid method for delineating maritime zones under modern law.	Clear and generates definite UNCLOS maritime zones (territorial sea, EEZ, continental shelf) measured from the archipelagic baselines.
Sovereignty Claims	Asserted sovereignty over all waters within the treaty lines, a claim difficult to sustain internationally.	Asserts sovereignty over islands, archipelagic waters, and territorial sea in a manner consistent with UNCLOS, making the claim more defensible.

VIII. Critical Issues and Ongoing Challenges

Despite its advancements, RA 9522 and the archipelagic doctrine face ongoing challenges:

Archipelagic Sea Lanes Passage (ASLP): The Philippines has not yet designated specific archipelagic sea lanes, meaning the right of ASLP may be exercised through all routes normally used for international navigation (Article 53(12), UNCLOS). This defers, but does not negate, the operationalization of this aspect of the regime.

The “Regime of Islands” Application: The classification of features in the KIG and Scarborough Shoal as either islands entitled to full EEZ/continental shelf or mere “rocks” entitled only to a territorial sea remains a subject of dispute, particularly with the People’s Republic of China. The 2016 South China Sea Arbitral Award found that many features in the KIG are “rocks” under Article 121(3) and that Scarborough Shoal is a “rock,” which impacts the extent of maritime zones they generate.

Historic Waters Claim: RA 9522’s saving clause (“without prejudice to…”) in its preamble is interpreted by some to preserve a residual claim to historic title, particularly to waters within the treaty limits but outside the new UNCLOS baselines. This maintains a potential ambiguity.

Delimitation with Neighboring States: The precise delimitation of EEZ and continental shelf boundaries with neighboring states (e.g., Indonesia, Malaysia, Vietnam, Palau) remains unresolved and requires bilateral negotiations or adjudication.

IX. Conclusion

Republic Act No. 9522 represents a critical and necessary evolution in the Philippines’ legal strategy to secure its maritime domain. It successfully transposes the foundational archipelagic doctrine—a concept the Philippines pioneered—into the concrete, internationally recognized framework of the 1982 UNCLOS. By replacing the ambiguous and contested “Treaty Limits” claim with a system of UNCLOS-compliant archipelagic straight baselines and applying the regime of islands to outlying territories, the Philippines has fortified its legal position under public international law. While challenges persist regarding sea lanes passage, the classification of offshore features, and maritime boundary delimitation, RA 9522 provides a robust and defensible baseline from which the Philippines can assert its sovereign rights and engage in these disputes on a sounder legal footing.

X. Recommendations

The government should prioritize the technical and diplomatic process of designating archipelagic sea lanes to fully operationalize its rights and obligations under Part IV of UNCLOS.

In all diplomatic and legal fora, the Philippines should consistently anchor its maritime claims on the provisions of UNCLOS as implemented by RA 9522, and avoid reliance on the pre-UNCLOS “Treaty Limits” theory, which weakens its contemporary legal standing.

The 2016 South China Sea Arbitral Award should be leveraged as a definitive legal basis for clarifying the status of features in the West Philippine Sea and for negotiating maritime boundaries.

Continued investment in capacity for maritime domain awareness, law enforcement within its EEZ, and legal diplomacy is essential to effectively administer the vast maritime zones generated by its UNCLOS-compliant baselines.