Oxfam Novib, Pax Nederland and The Rights Forum filed the civil complaint in December, arguing that shipping F-35 parts which are owned by the United States, but stored in a warehouse on Woensdrecht air base, makes the Dutch complicit in war crimes in Gaza.

“The Netherlands is increasingly isolating itself from a variety of states, NGOs, the UN, the ICC [International Criminal Court] and the ICJ [International Court of Justice] all in the name of diplomatic relations,” human rights lawyer Liesbeth Zegveld, who is representing the groups, said.

The UN’s highest court, the ICJ, has issued three sets of emergency measures ordering Israel to respect international law in Gaza. The ICC has opened an investigation into Palestine and a request for arrest warrants for Israeli prime minister Benjamin Netanyahu, minister of defense Yoav Gallant and three Hamas leaders.

In January a lower court rejected the complaint, saying the situation was unclear. But the groups won on appeal in February. “It is undeniable that there is a clear risk that the exported F-35 parts are used in serious violations of international humanitarian law,” judge Bas Boele said at the time.

The government appealed against that ruling. Halting the exports would “severely damage our own security,” state lawyer Hans van Wijk told judges.

The Dutch granted a permit in 2016 to send the US-owned plane parts to Israel. Following the October 7 attacks, the military requested more and the Dutch customs office asked the government if it wanted to review the permit.

The state declined. “On the basis of current information on the deployment of the Israeli F-35, it cannot be established that the F-35 is involved in serious violations of the humanitarian law of war,” the caretaker government wrote in a briefing to parliament at the time.

Both sides will have the opportunity to reply to arguments in writing and then the court’s advocate general will give an opinion before a final ruling is made.