Greta Thunberg has never shied from controversy, and her recent participation aboard the pro-Gaza humanitarian ship Madleen has placed her at the center of one of the most contentious humanitarian controversies in recent memory. Famously an activist for climate issues, Thunberg was amongst a flotilla of humanitarians, activists, and public figures attempting to breach Israel’s naval blockade of Gaza and deliver necessary aid to a besieged population.
The Flotilla was organized by the Freedom Flotilla Coalition, an organization with a history of organizing sea and land convoys to Gaza. This particular journey constituted the Global Sumud Flotilla, a designation used by its facilitators to describe the largest ever civilian flotilla assembled. 44 nations had representatives and more than 50 ships participated, all intent on bringing visibility to Gaza’s humanitarian need crisis. The Madleen, a yacht flying the British flag, departed Sicily on June 1, 2025, carrying a symbolic cargo of food, baby formula, and medicine. On board were Thunberg, French Member of Parliament Rima Hassan, and Brazilian activist Thiago Ávila.
Tension was high from the beginning. The organizers were aware of the risks; previous flotillas had been intercepted, sometimes violently. When the Madleen neared the Mediterranean waters off Egypt’s north coast, Israeli naval ships embarked to intercept. The Freedom Flotilla Coalition reported that the vessel was boarded in international waters around 200 miles off Gaza at dawn on June 9. Footage obtained by the group showed activists raising their hands as Israeli commandos took over the yacht. The coalition described the action as a kidnapping, with activists being “unlawfully boarded” and “abducted” in violation of international law.
Israel, meanwhile, dismissed the flotilla as a publicity stunt. The Foreign Ministry released photos of Thunberg and the other activists upon their arrival in Ashdod port, saying they were being treated well and would be deported. Defense Minister Israel Katz stated that the activists would be shown videos of the October 7, 2023, Hamas-led attack on southern Israel, blaming them for turning their backs on the atrocities committed by Hamas. Katz addressed CNN bluntly, “Greta was not bringing aid; she was bringing herself. And she’s not in Gaza for Gaza, let’s be honest about that. She’s here for Greta.”
The arrest of the activists had already triggered an escalation in diplomatic response. France, whose six nationals were on board, called for their immediate release and condemned the blockade as a “scandal.” Turkey condemned the interception as “heinous,” while Iran described it as “piracy” in the high seas. The United Kingdom urged Israel to exercise restraint and to respect international law. Human rights organizations, including Amnesty International, denounced the seizure, with Secretary General Agnès Callamard denouncing blockading the Madleen in international waters as “contravening international law and putting at risk the safety of those on board.”
Legal controversy followed. Adalah, a Palestinian legal organisation working in the name of the activists, argued that Israel had no jurisdiction to seize a UK-flagged vessel in international waters, and particularly one headed towards Gaza, which is part of the State of Palestine territory. United Nations special rapporteur on occupied Palestinian territory Francesca Albanese also agreed with this position by emphasizing that Israel had “absolutely no authority to intercept a boat carrying humanitarian aid and, above all, humanity to the people of Gaza.”.
After being detained and subjected to medical examination, Thunberg and several of the activists were deported. Thunberg was said to have traveled back to Sweden from France, while others remained at Givon prison in Ramla and refused deportation. Those who had not received deportation orders were about to be brought before a judicial committee to sanction their expulsion.
This tragic event unfolds against the backdrop of a mounting humanitarian emergency in Gaza. Over 600 days of conflict and an 11-week blanket siege have left Gaza’s 2.1 million residents in a state of extreme hunger and poverty. Even as Israel began to permit limited aid toward the end of last month, humanitarian organizations report that the deliveries are too small to prevent famine. Other relief organizations and the United Nations have refused to work with the newly established Gaza Humanitarian Foundation on grounds of objection to neutrality and the militarization of aid delivery. UNRWA, the UN Palestinian refugee agency, has been adamant in requesting unrestricted access to deliver relief and maintain dignity.
Interception of the Madleen is one such chapter of an enduring struggle for access to Gaza. Past flotillas suffered the same fate—ships intercepted, activists detained, aid confiscated. The defenders of the missions argue they are acts of civil disobedience, calling attention to the international community to what they see as an illegal blockade and an impending humanitarian emergency. Israel argues that it has to blockade Gaza to keep weapons from falling into Hamas’s hands, but that adequate means already exist for humanitarian relief to be delivered safely.
For Greta Thunberg, it is a new frontier of activism. She has been acclaimed for her intransigent climate activism, but she has increasingly been focusing on humanitarian issues and social injustices, including the wars in Ukraine and Gaza. In a video message published by the Freedom Flotilla Coalition, Thunberg called on supporters to pressure the Swedish government to free her and reaffirmed her devotion to nonviolent action and solidarity with oppressed peoples.
Even though Madleen did not break the blockade, the operation invigorated global controversy regarding humanitarian intervention and its legitimacy and morality, the position of occupying powers, and the role of activism in long conflicts. Gaza’s worsening humanitarian situation means that the questions this current flotilla posed—and the global response it prompted—aren’t likely to be forgotten for a long time to come.