Introduction
In late August, 2025, more than 50 vessels representing at least 44 countries set sail to Gaza with the hopes of delivering urgent humanitarian aid for the civilian population (Melimopoulos, 2025). By October 3rd, 2025, the Israeli military intercepted the last boat in the Global Sumud Flotilla, detaining around 450 activists in the process (Reuters, 2025). This incident sparked a diplomatic crisis and international condemnation of Israel’s actions, with nations like Colombia expelling Israeli diplomats, bringing the legality of Israel’s actions to the forefront of international debate (Melimopoulos, 2025).
The interception of the Sumud Flotilla not only exposes the precarious nature of humanitarian access to Gaza but also underscores the broader implications of restricting aid and movement in conflict zones. With the humanitarian crisis in Gaza reaching catastrophic levels, the obstruction of relief efforts by sea represents a breach of international legal frameworks designed to protect civilians during wartime. As such, this article examines the Sumud Flotilla interception through three interrelated dimensions of international law: the violation of freedom of navigation, the illegality of the naval blockade itself, and the denial of humanitarian access.
The Violation of Freedom of Navigation on the High Seas (Law of the Sea)
The United Nations Convention on the Law of the Sea (UNCLOS) serves as the primary legal framework for maritime activity. As stated in the Convention’s Preamble, it addresses “all issues relating to the law of the sea” and is ratified by the vast majority of UN member states (United Nations, 1982). Under UNCLOS, the high seas are defined as waters that lie beyond any state’s territorial jurisdiction, where all nations enjoy equal rights of navigation and access. This is outlined in Article 87 of the Convention, stating that both for coastal and land-locked states, freedom of navigation of the high seas is permitted (United Nations, 1982). Moreover, Article 90 states that every state has the right to “sail ships flying its flag on the high seas” (United Nations, 1982).
The interception of the Sumud Flotilla by the Israeli navy, which occurred in international waters, constitutes a direct violation of these principles. Since the flotilla was sailing under national flags on the high seas, Israel’s actions effectively infringed upon the collective navigational rights of the over forty states represented. Under UNCLOS, any interference with vessels on the high seas is only permissible in circumstances where there is reasonable ground to suspect that the ship is engaged in piracy, slave trading, not representing a nationality, or unauthorised broadcasting (United Nations, 1982, Art. 110). None of these conditions applied to the civilian-led flotilla, which flew represented national flags and had declared its mission to be peaceful and humanitarian in nature (Global Sumud Flotilla, 2025).
By intercepting the flotilla, Israel not only violated the sovereign rights of the nations represented but also undermined freedom of navigation, one of the core tenets of the international maritime order. Such actions taken by Israel reflect a growing disregard for international law, raising questions about the enforceability of global norms when violations occur with impunity.
The Illegality of the Naval Blockade
The interception of the Sumud Flotilla cannot be viewed in isolation; it forms part of Israel’s longstanding naval blockade of the Gaza Strip. Imposed in 2007 following Hamas’ election victory, Israel claims that the blockade is a necessary security measure to prevent weapons smuggling (International Committee of the Red Cross, 2025). However, its scope and impact far exceed any legitimate military purpose, drawing widespread condemnation for constituting an unlawful form of collective punishment under international law.
The San Remo Manual on International Law Applicable to Armed Conflicts at Sea (1994) outlines the permissible methods of warfare at sea and the conditions they must meet. Under Part IV, Section II, a blockade may only be considered lawful if it is declared to all belligerents and neutral states, does not bar access to neutral ports or coasts, and crucially, it must not have the sole purpose of starving the civilian population or denying it objects essential to its survival (International Committee of the Red Cross, 1994). Furthermore, Article 102 of the Manual explicitly states that if the effects of the blockade on the civilian population are disproportionate to the anticipated military advantage, the blockade becomes unlawful.
The humanitarian crisis in the Gaza Strip has left more than two million people without access to sufficient water, food, or medical care (International Rescue Committee, 2025). Reports from humanitarian organisations such as Amnesty International (2025) state that Israel’s blockade restricts access to essential goods far beyond what could be justified by legitimate military necessity and therefore amounts to a form of collective punishment. In this context, the blockade violates not only the San Remo principles but also Article 33 of the Fourth Geneva Convention (1949), which prohibits the collective punishment of civilian populations.
Moreover, the interception of the Sumud Flotilla demonstrates the blockade’s enforcement beyond Israel’s territorial waters. Article 96 of the San Remo Manual (1994) allows a blockading force to be stationed “at a distance determined by military requirements”, but the seizure of civilian vessels on the high seas suggests an excessive application of the blockade. It also emphasises that the blockade must not result in acts “inconsistent with the rules” set out in the document, including the protection of civilians (International Committee of the Red Cross, 1994). Given that the blockade severely restricts the entry of essential humanitarian supplies including food, medicine, and fuel, it contradicts the fundamental principles of both the San Remo Manual (1994) and the Fourth Geneva Convention (1949). The persistence of such a blockade illustrates not only the illegality of Israel’s actions but also the weakness of enforcement mechanisms in the current international order.
The Violation of Humanitarian Access
The right to humanitarian access lies at the heart of international law. Article 23 of the Fourth Geneva Convention (1949) and Article 70 of Additional Protocol I (1977) guarantee the free and unimpeded passage of essential food, medicine, and relief supplies to civilian populations. Israel’s interception of the Global Sumud Flotilla, a mission explicitly humanitarian in nature, thus represents a direct breach of these obligations.
The consequences of this denial of humanitarian aid are devastating. According to the UN Office of the High Commissioner (2025), more than one quarter of Gaza’s population is facing famine, while 94% of hospitals have been destroyed or rendered inoperable due to severe supply shortages, a lack of healthcare workers, and thousands of casualties (World Health Organization, 2025). Therefore, by blocking humanitarian relief, Israel’s actions effectively transform hunger and deprivation into tools of warfare. Under Article 54 of Additional Protocol I (1977), using starvation as a method of warfare is strictly prohibited.
Legal scholars and international institutions have increasingly recognised these policies as components of a broader genocidal framework. The deliberate deprivation of food, medical care, and humanitarian assistance, combined with continued military operations and displacement, suggests a systematic attempt to destroy the population of the Gaza Strip. In this light, the denial of access to humanitarian aid is not only an act of collective punishment but a weapon of extermination framed as necessary to the security of Israel.
Conclusion
The interception of the Global Sumud Flotilla and the continued enforcement of the blockade on the Gaza Strip not only reveal a multitude of violations of international maritime and humanitarian law but also expose a deeper crisis in the international order. By depriving millions of Palestinians of essential goods and services, Israel’s actions have challenged the authority of the legal frameworks that are the basis of modern international relations.
The erosion of respect for international law frameworks such as the UN Charter, the Geneva Conventions, and the Law of the Sea signals a dangerous shift in which states act beyond legal constraint under claims of “self-defence” or “security”. When violations of this scale go unpunished, they embolden other actors to disregard international norms, further destabilising an already fragile world order. Ultimately, Israel’s interception of the Global Sumud Flotilla and the blockade of Gaza exposes the disregard for the principles of humanitarian access, the rule of law, and for accountability.
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