IDF raids Gaza-bound flotilla in international waters — Where is the line between enforcement and unlawful seizure?

Israel’s interception of the Freedom Flotilla has intensified debate over the limits of state power at sea, raising questions about jurisdiction in international waters and the legality of the Gaza blockade.

Between 29th and 30th April 2026, Israeli naval forces intercepted 22 boats belonging to the Global Sumud Flotilla in international waters to the west of Crete. The boats were carrying activists and humanitarian supplies in an attempt to challenge the blockade of Gaza and deliver aid. On 1 May, 173 of the 175 participants were transferred to Crete while two of them, Thiago Ávila from Brazil and Saif Abukeshek, a Palestinian with Spanish and Swedish citizenship, were deported and detained in Israel on charges of “membership of a terrorist organization”. 

The location of the incident was roughly 500-600 nautical miles from Gaza, and about 45 nautical miles west of the Greek island of Kythira, fully open sea, governed by the high seas regime of the UN Convention on the Law of the Sea, UNCLOS. Under this Convention, vessels on the high seas fall under the jurisdiction of their State.  Therefore, Israel had no automatic legal right to board or seize these ships simply because of their proximity to Greece or their intended destination. Based on participant testimonies and evidence, boarding was not a neutral or minimally forceful procedure, as Israeli forces approached in military vessels, pointed firearms and lasers at civilians and ordered passengers to kneel on deck. Communications and navigation systems were reportedly jammed.  Additionally,  detainees and their legal representatives have alleged mistreatment, which includes physical restraint, blindfolding, and isolation during transfer and detention. Organizers immediately described the operation as “piracy,” invoking UNCLOS definitions concerning unlawful seizure at sea for coercive or political purposes.  

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Meanwhile, the interception occurred well outside Greek territorial waters, which limited Greece’s formal jurisdiction. Greek authorities emphasised that their role was limited to search and rescue operations and providing humanitarian assistance, rather than enforcing the law against foreign naval forces. Nevertheless, Greece facilitated the disembarkation of detained activists, coordinated medical care and arranged their repatriation, all the while calling for respect for international law, creating a dual dynamic where legal principles are upheld rhetorically, and the consequences of unchallenged actions are managed. At the European level, the response has been notably restrained.

Although the European Union has previously condemned violations of maritime law in other contexts, particularly concerning Russia, it has reacted cautiously to this incident, triggering debate about the perception of double standards in the enforcement of international law.

Israel claims that it is essential to keep Gaza under blockade to stop weapons getting in and out, and to stop militants entering and leaving the area, especially after 7 October 2023.   From that perspective, any Gaza-bound convoy could be framed as a potential threat, and its interdiction presented as legitimate enforcement.  Under international humanitarian law, the legality of a naval blockade is assessed against specific criteria, including effectiveness, prior notification, impartial application, and proportionality. These criteria derive primarily from customary international humanitarian law and are reflected in the San Remo Manual on International Law Applicable to Armed Conflicts at Sea.

In relation to the specific seizure of the flotilla, no evidence has been publicly presented that it was engaged in any prohibited activity. Invoking “security” in this manner risks undermining the broader architecture of maritime law, which is intended to protect freedom of navigation from unilateral interference.

Moreover, some might argue that the precedent of the 2010 Mavi Marmara raid is relevant. There, Israeli authorities similarly claimed that the activists posed a threat. However, subsequent investigations found that the use of force in that event was disproportionate and the underlying justification was widely criticized. Reapplying that logic to the 2026 flotilla without specific, evidence-based suspicion collapses the distinction between a credible threat assessment and generalized suspicion. The Global Sumud Flotilla is publicly portrayed as a non-violent humanitarian mission with transparent declarations of cargo and intent.  Beyond that, major human rights organizations, including Amnesty International, described the capture as involving the “arbitrary detention” of the activists and called the operation “brazen and unlawful.” Its Senior Director, Erika Guevara Rosas, linked the broader context to what she described as “atrocity crimes… including genocide in the Gaza Strip”, underscoring the severity of the humanitarian catastrophe, reinforcing the urgency of aid delivery.

Gaza’s reality makes the flotilla’s significance impossible to separate from the conditions on the ground. More than two million people live under severe restrictions on movement and a long-standing siege. Humanitarian agencies have repeatedly warned of acute shortages of food and medicine, pointing to tens of thousands of deaths, alongside the extensive destruction of hospitals, water systems and energy networks. These conditions form the backdrop against which civilian-led aid missions emerge. Living conditions are described in repeated UN situation reports as “dire” and “catastrophic,” with civilians unable to access basic goods and exposed to ongoing violence and environmental risks.  In parallel, a UN-EU World Bank Rapid Damage and Needs Assessment indicates that more than 371,000 housing units have been damaged or destroyed, alongside widespread destruction of essential infrastructure.  The same assessment estimates that human development in Gaza has been pushed back by approximately 77 years. 

Even when a blockade is lawful, international humanitarian law requires that essential support be allowed through and halting a humanitarian convoy far from any fighting raises concerns about whether the force used was excessive and whether it worsens the humanitarian devastation that international law seeks to prevent. Confronted with these circumstances, the interception takes on deeper significance, transcending the immediate maritime encounters. The seizure of the flotilla pits two competing security frameworks against each other, namely a state-centred model that justifies pre-emptive enforcement and a humanitarian model based on protecting civilians and ensuring the free passage of essential aid. Using coercive force against unarmed activists and obstructing a mission in response to a humanitarian disaster puts significant strain on the latter. Without an independent investigation into the legality of the event, the use of force, the treatment of detainees, and the broader application of maritime and humanitarian law, there is a risk that states will set a precedent that allows them to extend their oppressive power under the banner of security.

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