The International Court of Justice (ICJ) captured the world’s attention earlier this year when it began hearing charges that Israel was committing genocide against the Palestinian people in Gaza. An interim ruling by the court found this accusation to be plausible, although its final judgement is still some way off. In the meantime, the ICJ has begun considering a second case looking at Israeli actions across the entirety of the occupied Palestinian territories. This too could have far-reaching, and more immediate, consequences for Israel and provide an important boost to diplomatic efforts to end its long running conflict with the Palestinians. In December 2022, the UN General Assembly requested an ICJ advisory opinion on the legality of Israel’s prolonged occupation. This includes an examination of its decades-long settlement project, dispossession of Palestinians and institutionalised discrimination. Just as importantly, UN members asked the court to outline their responsibilities in response to such actions. Nineteen years earlier, the UN General Assembly had asked the ICJ to opine on the legality of Israel’s West Bank separation wall. While Israel has defended this as a necessary security measure, the court ruled in 2004 that it had de facto annexed Palestinian territory, preventing the Palestinian people’s right to self-determination. But absent any follow-up action by the states themselves, its call for Israel to dismantle the wall has gone unheeded. Last week, legal representatives from 49 countries took the stand to testify about Israeli actions during a six-day hearing. As expected, Israel’s allies, such as the US and UK, fought what will likely prove to be an unsuccessful rearguard effort to halt the ICJ in its tracks. They urged the court to avoid inserting itself in what they claimed was a political dispute that should instead be resolved through the (failed and currently non-existent) Palestinian-Israeli peace process. The UK and US used the same diversionary tactics in an effort to block the ICJ’s 2004 investigation and another one into the UK’s continued control over the Chagos Islands in the Indian Ocean. Having failed to convince the court each time then, such arguments are unlikely to prove any more successful this time round. And such positioning has further spotlighted UK and US double standards given their support for an ICJ ruling against Russia’s invasion of Ukraine. Israel and its backers were largely isolated in the world court. Country after country voiced support for Palestinian self-determination, repeatedly calling for an end to Israel’s occupation, settlement and annexation of Palestinian land. The contributions illustrated a growing recognition that Israel’s practices amount to an institutionalised policy of racial discrimination. The UAE, which inked a landmark agreement to establish ties with Israel in September 2020, castigated Israel’s “brutal…regime of systemic subjugation”. European states such as Belgium, France and Spain voiced similar views. States like Belize, South Africa and Namibia went furthest, describing the situation as apartheid, in line with the findings of several international human rights organisations. A few years ago, such international reprobation would have been difficult to fathom. But the horror of Israel’s war on Gaza is propelling a deep shift of international opinion against Israel. This is especially true of the global south, where South Africa and Namibia have spearheaded the legal challenge against Israel over charges of genocide. But it is also true of Europeans who have too often shied away from strong criticism of Israel. Equally crucial is what states had to say about their own responsibilities, including the need to differentiate between Israel and the occupied territories as laid out in UN Resolution 2334. In practice, this means fully excluding settlement-affiliated entities from all bilateral relations with Israel, and banning the import of settlement products (as proposed by Ireland). These steps are a low bar but have yet to be enacted. Other states, like Bolivia, suggested banning arms trade with Israel while Chile and the Netherlands raised the option of Israeli reparations for Palestinians (as previously stipulated by the ICJ). Judges have now withdrawn to consider their judgement, which could come by the summer. Based on past precedent, the ICJ will no doubt re-affirm the illegality of the settlements and the associated system of discrimination (even if it stops short of using the word apartheid), and potentially call for these to be dismantled. It could go even further should it consider Israel’s entire presence in the occupied territories to be illegal and demand this be ended as soon as possible. This would, in effect, pull the rug from under Israel’s feet. Such a ruling would no doubt reinforce a parallel investigation by the International Criminal Court (ICC), which could eventually result in arrest warrants against Israeli officials (as well as Palestinian militants). On the question of third-state responsibilities, the ICJ has tended to be more conservative. Rather than providing a play-by-play guide, it may merely set out guiding principles – including a general duty to co-operate to end any unlawful situation it identifies. It would then leave it to the UN Security Council and General Assembly members to elaborate on how to do this in practice, potentially building on suggestions already set out by the countries themselves. These legal debates may seem far removed from the immediate suffering of Palestinians and the pressing task of ending Israel’s violence against Gaza’s civilian population. But long-term peace and security for both peoples will require a reinvigorated political track leading to Palestinian independence and self-determination – the freedom to shape their own future. And there is little prospect of this happening without sustained external pressure on Israel. Ultimately, Israelis will only move towards ending their occupation when they consider this as an urgent national interest. That will require strong support for international mechanisms to hold Israel to account for its severe violations of international law and deprivation of Palestinian rights. Avoiding past failure will require third states to play their part by enforcing the court’s rulings to impose real costs. Through its deliberations and a future advisory opinion, the ICJ can show the way to do this. But ultimately it will be up to the international community to follow its lead and act decisively.