Hamas’s counteroffer to President Trump’s latest peace foray might come sooner than its much awaited official reply. The so-called Sumud Flotilla, starring Hamas booster née-environmental activist Greta Thunberg, is about to reach Gaza, and a potential clash between the navies of Israel and NATO members could sink all hope of ending the war. Plus, we now know that Hamas is behind this potentially bloody provocation.

Israel on Tuesday published documentation it found in Gaza proving the tight coordination between Hamas and the 42 vessels known as the Sumud Flotilla. The name could have given a clue to its goal. In the aftermath of Israel’s 1967 victory over neighbors seeking its destruction, Palestinian Arabs adopted the term “sumud,” or “steadfastness,” as a defiant challenge to the Jewish state. Erasing Israel has been and still is Hamas’s top goal. 

As of Tuesday, the pleasure boaters are as close to Israel as 150 nautical miles, which means the flotilla could reach shore as Jews observe Yom Kippur. The passengers claim to deliver aid to Gazans. Yet trucks filled with more food and medicine than all their hulls can ever carry enter Gaza under Israeli supervision each day. Last time Ms. Thunberg attempted this stunt, in June, she was politely diverted to the Israeli port of Ashdod and deported. 

This time, though, things could become messy. Navy ships and drones of Israel-averse governments at Ankara and Madrid are now escorting the flotilla. Buckling under pressure, even Prime Minister Georgia Meloni dispatched vessels for the rescue of Italian flotilla passengers. True, in 1588 the Spanish armada was sunk by British and Dutch navies under the command of Elizabeth I. Yet, might the Israel Defense Forces risk confrontation with NATO members?

Such a confrontation could end up being the best outcome for Hamas. From day one it has tried to turn Westerners against Israel, and the “Greta Flotilla” is part of that effort. An IDF spokesman, Lieutenant Colonel Nadav Shoshani, is posting X documents showing that a group known as the Popular Conference for Palestinians Abroad “acts as Hamas’s representative abroad, organizing demonstrations, marches, and flotillas.”

Two PCPA members, the London-based Zaher Birawi and a resident of Spain, Saif Abu Kashk, are directly linked to the flotilla. Mr. Kashk’s front company, Cyber Neptune, owns a large number of the flotilla’s boats. The documents prove that the flotilla has “direct connection to Hamas, from leadership and funding to ship ownership,” Colonel Shoshani writes, posting a photo of Ms. Thunberg on board next to Mr. Birawi in June. 

Arab and Muslim countries, including Hamas-supporting Qatar and Turkey, back Washington’s plan to end the war. So are the French, the British, and other Europeans who are caving to the anti-Israel mobs in their streets. Prime Minister Benjamin Netanyahu is on board. Mr. Trump reportedly gave Hamas three days to answer. Would-be do-gooders on yachts, clandestinely backed by Hamas, might deliver the reply.