Indo-Pacific Legal Topics for Operational Lawyers
The year 2024 was a time of increasing instability for global security. The ongoing war between Russia and Ukraine has resurrected the specter of a world war, in which North Korea is also involved. Perhaps related to that war, November of last year saw an incident in Sweden’s exclusive economic zone involving the cutting of an undersea communication cable, attributed by some to the Chinese merchant ship Yi Peng 3. Meanwhile, in the Middle East, the conflict in Palestine has no end in sight. The Red Sea can be said to be in a state of collapse due to indiscriminate missiles and drone attacks on commercial vessels by the Houthis.
The situation in the Indo-Pacific is also quite severe. In the South China Sea (SCS), China continues its aggressive actions against the Philippines. According to a 2024 report to the U.S. Congress, Beijing continues to aggressively enforce extraterritorial sovereignty claims across the Pacific and, in 2023, used water cannons, aggressive maneuvers and ramming, and military-grade lasers against the SCS claimant nation ships, most prominently those of the Philippines.
Tension in East Asia is also high. In a 2024 “Defense White Paper of Japan,” Defense Minister Kihara Minoru described the security environment surrounding Japan as “now facing its greatest trial since the end of World War II. The existing order is being seriously challenged. Japan finds itself in the most severe and complex security environment of the post-war era.”
In February 2023, U.S. Central Intelligence Agency Director William Burns said that Chinese President Xi Jinping had ordered his military to conduct an invasion of self-governed Taiwan by 2027. In October 2024, China conducted a large-scale military exercise with 24 naval vessels and 125 aircraft around Taiwan. A Japanese specialist, Iida Masafumi of the National Institute of Defense Studies, analyzed the exercise and said “China is trying to improve its capabilities in blockade operations against Taiwan.” Subsequently, in December 2024, China sent its largest naval fleet in decades around Taiwan. If Secretary Burns’ testimony is true, a Chinese invasion of Taiwan could occur at any time.
Against the backdrop of a severe security environment in the Indo-Pacific, this post offers three pressing legal topics and outlines the legal frameworks that underpin them for operational law officers who have yet to experience service in the region. The topics include: grey zone and hybrid warfare; non-combatant evacuation operations (NEO) in a Taiwan crisis; and China’s Blockade against Taiwan.
Grey Zone and Hybrid Warfare
Issues
It has been eight years since the Permanent Court of Arbitration announced an award respecting the SCS. But there has been no perceived stability regarding the claims the court addressed. China is militarizing the islands of the SCS without regard to the arbitral award and has not hesitated to violate its international legal obligations. China has also harassed the Philippines in multiple domains and fora, including through its maritime police.
In response, the Philippines is attempting to counter China, for example, by increasing joint exercises with the United States, Japan, and Australia. Perhaps one of the most distinctive examples of China’s harassment of the Philippines thus far has been the activities of maritime militias that masquerade as fishermen in disputed areas. According to Erickson, hundreds of incidents have occurred. Using maritime militias to look like mere fishermen can be categorized as an example of so-called “hybrid warfare.”
The question here is the classification of these fishing boats. Maritime militia raise two related legal issues. The first is the difficulty of identification. Fishing vessels used by the maritime militias do not distinguish themselves in appearance from genuine fishing vessels, thus increasing the complexity of classifying them and ultimately ascribing State responsibility.
The second issue is the complexity arising from the differences in targeting law between land warfare and naval warfare. Land-based targeting rules and principles are not directly transferable to naval warfare. The historical background to targeting law in each domain is reflected in their respective variations. The targeting law of land warfare is now explicitly stated in treaties such as Additional Protocol I to the Geneva Conventions (AP I), whereas the law of naval warfare is mostly found in customary international law.
AP I, Part IV, Section I describes general protections against the effects of hostilities including a definition of civilians, definition of military objectives and precautions in attack, none of which apply directly to naval warfare. Some manuals, including the San Remo Manual on International Law Applicable to Armed Conflicts at Sea (San Remo Manual) and the Newport Manual on Law of Naval Warfare (Newport Manual) nevertheless reflect these provisions. For example, in terms of naval targeting, military objectives are decided by the status of the vessels, not the individuals onboard. Therefore, operational lawyers need to evaluate the vessels’ nature, location, purpose and use to decide whether they can be targeted. Moreover, if a maritime militia displays amphibious capabilities and starts landing, the rules of land warfare apply (including a reversion to individual-based targeting and the concept of direct participation in hostilities). From that moment, operational lawyers need to start evaluating each individual member of the maritime militia on the basis of law of land warfare. Accordingly, vessels operated by maritime militias present legal officers with several challenging determinations.
Legal Analysis
The most difficult legal issue related to maritime militias is to determine the legal status of these vessels. One effective approach is to establish naval zones (e.g. Maritime Exclusion Zones (MEZ)) thereby giving warning to “ordinary” vessels to leave the operational area. For example, British forces and Argentina established naval zones during the Falklands War (1982). Although the establishment of a Total Exclusion Zone by British forces and a War Zone by Argentina was legally problematic, these are measures that can contribute effectively to reducing accidental lethal effects to non-combatants/neutral shipping.
The establishment of naval zones finds recent support in both State practice and opinio juris. As mentioned in the San Remo Manual and documentation between the Japan Joint Staff and U.S. Indo-Pacific Command, the establishment of naval zones itself is lawful but does not confer any new rights. U.S. Navy Captain (ret.) Pedrozo claims MEZs are lawful “to the extent MEZs are used to warn neutral vessels and aircraft to reduce their exposure to collateral damage and incidental injury and are enforced consistent with the relevant principles of the law of armed conflict.”
In summary, as a matter of law, the establishment of zones does not confer new rights on belligerents, but it does provide an important factual basis for considering the intent of merchant vessels that ignore warnings and enter areas where zones and detours have been established. Fishing boats in the MEZ, classified as merchant vessels under the law of naval warfare, may seek to enter the areas of operations to offer “a definite military advantage.” If they do, operational lawyers may evaluate them as military targets.
NEO in Taiwan Crisis
Issues
The safety of its citizens is a significant concern for every State. States typically conduct NEOs before or after armed conflicts. For instance, in 2021, the United States and collaborating countries evacuated approximately 124,000 people from Afghanistan.
Admiral (ret.) Takei Tomohisa, former Chief of the Maritime Staff, Japan Maritime Self-Defense Force (JMSDF), discusses the challenges of a NEO in the context of a Taiwan crisis in the U.S. Navy publication Proceedings. He indicates that 827,000 foreigners, including 8,900 U.S. citizens, reside in Taiwan. However, evacuation options are limited to air and sea operations. The rules of naval warfare further complicate this problem. As addressed above, under the law of naval warfare, if a warship is used for civilian evacuation, it remains a military target and is not subject to the same protective markings as in the law of land warfare. Military targets in naval warfare include warships, auxiliary ships, and merchant ships escorted by warships. This post will not address the legal status of any conflict in Taiwan.
Legal Analysis
A potential solution to this issue is to establish humanitarian corridors at sea for NEOs, in cooperation with international organizations. Humanitarian corridors have been useful in assisting people in conflict zones on land. The International Committee of the Red Cross (ICRC), terms humanitarian corridors as essentially reflecting agreements between parties to an armed conflict that allow for safe passage for a limited time in a specific geographic area. They can facilitate the evacuation of civilians, the delivery of humanitarian assistance, or the transport of the wounded, sick, or dead.
The ICRC has reported the use of humanitarian corridors in the Spanish Civil War (1937), Syria (2016), Ukraine (2022) and the Black Sea (July 2022 to July 2023, for grain exports by Ukraine). In the Black Sea, the International Maritime Organization established what it called a “maritime humanitarian corridor” from July 22, 2022 to July 17, 2023. However, the corridor was for grain exports by Ukraine and had nothing to do with activities related to other humanitarian assistance. Therefore, the case in the Black Sea is, as a matter of law, should not be categorized as a humanitarian corridor.
As an additional consideration, under the law of naval warfare certain categories of targets are immune from attack, such as vessels used for humanitarian purposes (e.g., hospital ships) and vessels granted safe conduct by agreement between belligerent parties. To ensure safer and quicker NEOs, it would be beneficial to designate routes as humanitarian corridors where safety is guaranteed for conducting NEOs and to establish clear categories of vessels for use in NEOs (such as refraining from using warships).
Practically speaking, if belligerents could commit not to attack vessels intending to conduct NEOs which pass through designated shipping lanes, neighboring States could evacuate a larger number of personnel more efficiently and safely. While securing the consent of belligerents for such arrangements might be challenging, cooperating with a humanitarian organization such as the ICRC could facilitate the negotiation and implementation of humanitarian corridors. Additionally, having ICRC members on board NEO vessels could help ensure their neutrality and monitor for any violations.
China’s Blockade against Taiwan
Issues
China’s large-scale military exercises around Taiwan have raised concerns about a potential blockade of Taiwan by the Chinese military. In August 2024, the Center for Strategic and International Studies published a report titled “How China Could Blockade Taiwan,” discussing the possibility of a quarantine led by law enforcement forces and a blockade by the People’s Liberation Army (PLA) aiming to cripple Taiwan by cutting off trade, especially energy and other necessary imports. Rear Admiral (ret.) Kawakami Yasuhiro points out that the PLA conducts large-scale air and maritime blockade operation exercises multiple times a year, targeting both short and long war scenarios. Furthermore, RADM (ret.) Kawakami notes that China would likely lay mines near the north and south entrances of the Taiwan Strait. While a naval blockade is a method of warfare in international armed conflict, this post does not discuss the status of any conflict. (For further discussion of blockade in this context, see here.)
Legal Analysis
A blockade by the Chinese navy can be implemented in two ways: a quarantine in the grey zone; or a blockade as a method of warfare.
During the Cuban Missile Crisis of 1962, the Kennedy administration conducted a naval quarantine of Cuba. President John F. Kennedy ordered the quarantine on October 22, 1962, by signing Proclamation 3504 to “defend the United States.” This is of course of a domestic legal remedy. The term “quarantine” is legally distinct from a blockade, which assumes a state of war. President Kennedy’s proclamation stated that all vessels bound for Cuba were subject to detention and diversion to a U.S. port if they carried nuclear contraband.
This measure could theoretically be applied against Taiwan. However, international law scholars, including Yoram Dinstein (p.226) and Quincy Wright, concluded this measure could not be reconciled with Article 51 of the UN Charter. Moreover, PLA attempts to conduct a quarantine indiscriminately against all vessels, including those not flying the Chinese flag or vessels of other governments in international waters, may violate the principle of the flag State under Article 94 and the immunity of ships used on government non-commercial service under Article 96 of the United Nations Convention on the Law of the Sea. Therefore, applying quarantine to all vessels bound for Taiwan would be difficult to legitimize.
Meanwhile, a blockade is a method employed during a state of war. Taiwanese Defense Minister Wellington Koo stated that a blockade would be an act of aggression according to Article 3(c) of United Nations General Assembly Resolution 3314 (XXIX). Consequently, a Chinese blockade against Taiwan may violate the principle of refraining from the threat or use of force enshrined in Article 2(4) of the UN Charter (jus ad bellum).
In terms of jus in bello, blockades are legitimate if enforced in accordance with certain rules, including obligations of notification, effectiveness, and impartiality. One crucial rule relevant to the Taiwan case is that a blockade is prohibited if it has the sole purpose of starving the civilian population or denying it other products essential for its survival. If the civilian population of the blockaded territory is inadequately provided with food and other essential supplies, the blockading party must provide for the free passage of such supplies. These rules are widely accepted in academic manuals such as the San Remo Manual (paras. 102, 103) and the Newport Manual (para. 7.4.5), as well as in States’ military manuals (see e.g., U.S. Department of Defense Law of War Manual (para. 13.10.2.5); UK Joint Service Manual of the Law of Armed Conflict (paras. 13.74, 13.75); French Manuel de Droit des Opérations Militaires (para. 1.2.3.2.2)).
In reality. Taiwan depends heavily on imports for food. According to the Ministry of Agriculture of Taiwan, the food self-sufficiency rate was 30 percent in 2023. Given that the remaining 70 percent comes from abroad, an economic blockade against the whole Taiwan could be considered an attempt to starve the population (making such an operation illegal).
The fear is that international society, including think tanks, may inadvertently convey the impression that such a blockade is widely accepted and legitimate. It is essential to clarify that a blockade targeting the civilian population, as a method of warfare, is illegal under the law of naval warfare.
Operational lawyers should firmly voice their opposition to any blockade intended to starve the people of Taiwan, emphasizing its illegality and the unacceptability of such methods in the Indo-Pacific region. To create a climate where illegal methods of warfare are not tolerated, operational lawyers should actively engage in various means, including conferences and workshops, to promote the correct understanding of law of naval warfare and blockades. By actively advocating for the rule of law and the protection of civilians, operational lawyers can help prevent the normalization of illegal warfare practices in the region.
Conclusion
In the Indo-Pacific region, as in all regions, lawfare is an ever-present factor in strategic and tactical events. Within the Indo-Pacific, however, lawfare plays a central role in great-power geopolitics. To effectively address complex issues in this region, operational lawyers must be prepared to provide legal insights and criticisms with a profound understanding of the relevant laws. This paper has explored three salient topics—grey zones and hybrid warfare, NEO at sea, and China’s blockade against Taiwan—to offer insights for operational lawyers who have limited experience in the Indo-Pacific region. To address these challenges, I suggest three key approaches:
1. Hybridization of operational lawyers: Given the interconnectedness of sea and land events in the Indo-Pacific region, operational lawyers must possess a strong command of both land and naval warfare laws. Developing such hybrid expertise will enable them to effectively address the unique challenges that arise in this dynamic region.
2. Collaboration with regional lawyers and organizations: In the absence of a collective security system like NATO, close country-to-country collaboration is crucial. Regular engagement with organizations like the ICRC—which promotes humanitarian objectives—is equally important. By fostering relationships and exchanging ideas, operational lawyers can create a robust network capable of tackling the region’s challenges.
3. Proactive sharing of legal knowledge: By disseminating accurate legal perceptions and raising awareness, operational lawyers can serve as deterrents. Existing initiatives, such as the U.S. Indo-Pacific Command’s International Military Law and Operations (MILOPS) conference, Cushing International Law Conference by the U.S. Naval War College, Annual International Law Workshop co-hosted by JMSDF Command and Staff College and U.S. Naval War College, and Lieber Workshop by the U.S. Military Academy, provide valuable platforms for exchanging views and networking.
While numerous challenges remain in the Indo Pacific region, it is essential to create more opportunities for operational lawyers to engage and contribute their expertise. In 2025, it is hoped that even more operational lawyers will participate in addressing the region’s complex issues.
The thoughts and opinions expressed in this post are solely those of the author and not necessarily those of JMSDF, Ministry of Defense, or Government of Japan.
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Yusuke Saito is a captain in Japan Maritime Self-Defense Force (JMSDF) and he currently works as the deputy director of the Operational Law Office, Maritime Self-Defense Force Command and Staff College (CSC).
Photo credit: U.S. Navy, Mass Communication Specialist 1st Class Kirk Worley
