Will world leaders gathering in New York act on mass atrocities?

As world leaders convene for the United Nations General Assembly (UNGA) in New York, we are witnessing a cascade of crises, from Israel and Gaza to Sudan, Afghanistan, Burkina Faso, Haiti, Myanmar and Ukraine.

And while, in many cases, those responsible for the atrocities are known, they remain free to wreak havoc on civilians. Moreover, those who claim to be working around the clock to bring peace through negotiations are in some cases the same powers continuing to supply perpetrators with weapons and political cover.

It doesn’t have to be this way. These are not unfortunate circumstances or natural disasters outside anyone’s control. They are crises fuelled by inaction, coiled over decades and spiralling over years. World leaders can take specific measures that will save human lives.

Israel’s unrelenting offensive causing huge Palestinian casualties in Gaza is empowered by Western states’ supply of arms. In Gaza, Israeli forces have unlawfully attacked civilian residences, medical facilities, and aid organisations, and used starvation as a weapon of war. Israel has now accelerated its abuses in the occupied West Bank, too.

The United Kingdom recently recognised its risk of complicity in violations associated with continued sales and suspended some arms licenses to Israel. Canada is doing the same. In May, the United States held back a single shipment of bombs to Israel. But such actions are half measures, as the bulk of weapons earmarked for Israel continue to be transferred without restriction. That needs to change.

In Sudan, millions have been displaced by a brutal internal conflict and fighters continue to block the delivery of aid even as famine is killing thousands. Sudan’s crisis isn’t just the product of a battle between two power-hungry generals who had a falling out; it’s also a conflict sustained by external powers. Both the Sudanese Armed Forces and Rapid Support Forces have acquired new modern weapons, produced by companies registered in China, Iran, Russia, Serbia, and the United Arab Emirates. UN experts have found that the UAE has channelled arms to the Rapid Support Forces in violation of a longstanding arms embargo.

It is time to cut off arms to the warring parties in Israel and Gaza, restrict jet fuel to Myanmar’s abusive military, and extend the arms embargo in Sudan to cover the whole country, which would alter the calculus of warring parties in ways that could save lives.

Much more can be done to address Russia’s unlawful air strikes in Ukraine, the Taliban’s systematic repression of women and girls in Afghanistan, the Myanmar military junta’s war crimes against and persecution of the ethnic Rohingya, the criminal groups terrorising Haiti’s capital, and massacres both by armed groups and the army in Burkina Faso.

World leaders should find a way to establish a robust civilian protection mission to aid Sudan’s civilians, as they did in the Central African Republic.

They should also actively enforce the International Criminal Court’s arrest warrants against alleged architects of atrocities – like Russia’s Vladimir Putin. And they should do more to uphold and implement the orders by the International Court of Justice to protect civilians in Syria, Ukraine, Myanmar and Gaza.

Over more than two decades of work on human rights, I’ve seen the impact of international solidarity and the power of principled, determined leadership to circumvent deadlock.

UN member states have proven they can act even when roads seem blocked – setting up investigations into war crimes in Syria and Myanmar, offering the hope of future accountability that truly can help deter abuses over the longer term.

It’s true that the UN Security Council (UNSC) often fails to act decisively, crippled by the veto power of its powerful permanent members. Russia deploys its veto on Ukraine, the US vetoes in defence of Israel, and in many other cases responsibility is deferred to regional organisations that lack the political will or, in some instances, the capacity to tackle complex conflicts. However, history also shows us that the council has not always had a monopoly on deploying peacekeepers. In 1956, the UNGA was the architect of the UN’s first Emergency Force to secure and supervise the cessation of hostilities in the Middle East.

South Africa’s case against Israel before the International Court of Justice under the Genocide Convention has led to three rounds of ”provisional measures” – clear orders directing governments to stop abuses, which have added to pressure on governments to rethink their military support of Israel.  Similar South-South solidarity is also evident in Gambia’s ongoing case against Myanmar at the same court. This is a significant confirmation by the court that a genocide anywhere is of concern to people everywhere, giving a small African country standing to assert claims on behalf of the Rohingya.

Even the UNSC can deliver when progress is in line with permanent members’ interests: in Haiti, the council authorised the deployment of a Kenyan-led mission to support the Haitian National Police in their fight against criminal groups – which has the potential to make a real difference in restoring security, access to necessities, and democratic governance if the mission and Haiti’s new transitional government are given the necessary resources. That mission is up for reauthorization at the end of the month and the Security Council may even begin to consider transitioning it into a full-fledged peacekeeping operation.

The UNGA has also instituted a new procedure put forth by Liechtenstein requiring Security Council permanent members to explain their vetoes, in an endeavour to make it politically costly for those who block efforts to protect civilians at risk. In the coming days, Palestine, in its first proposal after its push for full UN membership this summer, will seek to spur international pressure to enforce the ICJ’s advisory opinion on Israel’s occupation through a non-binding resolution at the UNGA – this effort is likely to pass.

This year’s theme for the UN: “Leaving no one behind: acting together for peace, sustainable development, and human dignity” is timely. Let this be the moment when world leaders muster the political will to meaningfully come together and act.

The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.