‘It's one of the most important foundational norms of the post-World War II international order, that states are not permitted to violently acquire and expand their own territory,’ says Heidi Matthews, professor at Osgoode Hall Law School of York University in Canada.
Israel’s decision to expand its “military operations” in Gaza and occupy the city violates international humanitarian law and the Palestinian people’s right to self-determination, experts said.
Heidi Matthews, a professor at the Osgoode Hall Law School of York University in Canada, and Martin Shaw, emeritus professor of international relations and politics at the University of Sussex in the UK, told Anadolu that Israel’s decision should be halted through diplomatic pressure from third states.
Matthews said the International Court of Justice (ICJ) advisory opinion from July 2024 made it very clear that the “occupation (of Palestinian territories) has become unlawful and must be brought to an end as rapidly as possible.”
Recalling that the UN General Assembly, in its resolution clarifying this opinion and setting out the obligations of third states, set September 2025 as the deadline for ending the occupation, she stressed that Israel’s decision to permanently seize part or all of Gaza also violates the prohibition on acquiring territory by force.
“Any plans to take over parts or all of Gaza would be in contravention also of the rule against the violent acquisition of territory as well. And, obviously that's a peremptory norm of international law. It's one of the most important foundational norms of the post-World War II international order, that states are not permitted to violently acquire and expand their own territory,” she said.
Matthews said that even taken at face value — with Israel claiming its plans are not annexation but rather defeating Hamas and then transferring the territory to a coalition of friendly Arab states — the decision is “very clearly a violation of the Palestinian peoples’ right to self-determination and to the territorial integrity and political independence of the Palestinian territory as well.”
She also cautioned that the "responsibility to protect" principle should be applied carefully when it comes to preventing attacks on civilians in Gaza.
Emphasizing that the root cause of attacks against Palestinians is political rather than humanitarian, Matthews said “the real, root violence of the plan is the way in which it further infringes on the Palestinian peoples’ right to political self-determination, right to freely choose their political future, not to be subjected, to another form of foreign occupation.”
- Western states’ inadequate measures
Matthews pointed out that Western states have not taken sufficient steps toward a peaceful solution, stressing that actions should include the unconditional recognition of a free and independent Palestinian state, ensuring humanitarian aid access, imposing serious diplomatic sanctions against Israel, personal sanctions on the entire Cabinet, including the Israeli Prime Minister Benjamin Netanyahu, and a review of all commercial relations.
She said that third states should not only take measures against Israel but also review their own domestic policies toward supporting Palestine, noting: “This includes rolling back some of the very distressing steps that have been taken to censor speech around Palestine, to criminalize, and to list as terrorist organizations those organizations and activist groups working for Palestinian human rights. All of those actions are part of the broader peaceful approach.”
Matthews said: “I really am not convinced that there's a violent military solution to fundamentally political problems.”
States should devote their resources to diplomatic and peaceful solutions rather than the military industry, she stressed.
- Operations ‘will aggravate ongoing crimes’
Shaw said Israel is already carrying out an illegal occupation in Palestine, committing extensive war crimes, and perpetrating genocide in Gaza.
He added: “The proposed new operations will undoubtedly constitute further violations and aggravate the ongoing crimes.”
Israel’s strategy of “forcibly removing Palestinians from Gaza City, apparently with a view to expelling them from Gaza altogether in the medium term” amounts to ethnic cleansing, he noted.
Referring to the issue of the "responsibility to protect," Shaw said: “Certainly there is a case for international intervention to stop Israel’s crimes, but it is not easy to see who would carry this out.”
He said that third states should withdraw all support and cooperation with Israel, apply comprehensive boycotts against Israeli products and institutions, and impose effective sanctions, including ending visa-free travel for Israelis.
International intervention is “certainly necessary and urgent under the duty of states to prevent genocide,” Shaw also said, stressing that the main problem is “the backing which (the US President Donald) Trump is giving Israel and the reluctance of states to prejudice their relations with the USA as well as Israel.”
