More than 10,000 Palestinians are dead as Israel continues to bombard Gaza following an attack by Hamas on 7 October.
Both sides have accused the other of war crimes after 1,400 Israelis were killed in Hamas’s shock assault.
While the law of war accepts there may be some civilian casualties, indiscriminate attacks are not permitted, and the International Criminal Court (ICC) is collecting evidence for possible prosecutions.
What is the legal character of the attack by Hamas?
The atrocity committed by Hamas on 7 October is a grave war crime and crime against humanity. Whatever the view on the justice of the Palestinian cause, there can be no justification for the slaughter of more than 1,400 individuals, mostly civilians, and the taking of more than 200 hostages under terrifying circumstances.
Is Hamas entitled to use force for the liberation of Palestine after decades of failed peace negotiations?
The Oslo Accords signed in 1993 saw the PLO (Palestine Liberation Organisation) recognise Israel and give up the right of an armed struggle on behalf of Palestine. The Palestinian Authority now represents the people.
Hamas has no such status and has been designated by many Western states as a terrorist organisation. Moreover, any group struggling for what it considers a just cause must still comply with humanitarian law. Terrorism against civilians is never permitted in law.
Is Israel entitled to self-defence?
Under Article 51 of the UN Charter, a state may use force in self-defence in response to, or imminent anticipation of, an armed attack by another state.
Since 9/11, it is accepted that this includes the right to respond to attacks perpetrated by non-state actors like Hamas.
Contrary to the position taken by Russia at the UN Security Council, Israel is entitled to self-defence in relation to Hamas’s attack.
But self-defence is limited to what is necessary to overturn the original armed attack, or prevent the next, imminent one, and the use of force must be proportionate to that attack.
How much force may Israel use in response to the Hamas attack?
Israel argues that it is now necessary to eliminate Hamas as a military and political force, in view of the persistent and serious threat the organisation poses to its people.
After 9/11, it was broadly accepted that the US could pursue al-Qaeda as far away as Afghanistan, and even remove the Taliban government. It was argued that it would otherwise not be possible to defeat al-Qaeda.
But Israel’s right to use force is not unlimited. It cannot implement its vision to “remake the Middle East” through forcible means, for instance by attacking third states such as Iran. The campaign must be focused on Hamas and its ability to launch further strikes against Israel.
What is the status of Gaza?
Gaza and the West Bank are part of Palestine, which is recognised as a state by 138 other states.
Under the Oslo Accords, Israel retains a security presence in parts of the West Bank but in 2005 it withdrew from Gaza. Most nevertheless still regard both territories as occupied, given their dependence on Israel, which controls access and exercises security functions there.
This includes repeated armed raids into Gaza in past years. This dependence has been confirmed by Israel showing itself able instantly to deprive the territory of water, sanitation, electricity, food and medical supplies.
Given the outrage committed by Hamas, is Israel still bound by humanitarian law?
Humanitarian law applies under all circumstances. Even if the other side does not comply, this is no reason to deny civilians protection. Israel has said it will comply with humanitarian law, despite the horrible provocation it has suffered.
Which branch of humanitarian law applies?
Before Israel’s 2005 withdrawal from Gaza, the International Court of Justice confirmed that the law of armed occupation applies. This seeks to protect civilians who are under the effective power of a foreign force.
Many analysts argue this is still the case. Others would apply the law of international armed conflict, given Palestine’s recognition by a large number of states.
Others say the more limited set of laws governing internal armed conflict applies, or a mix of the above. The principles of humanitarian law apply under all circumstances.
What are the key provisions of humanitarian law?
Humanitarian law establishes the principle of distinction. This means that the armed forces of a state can only target enemy combatants, not civilians.
Shelling of civilian concentrations, or indiscriminate bombardment of cities to terrorise populations, is prohibited.
Under the related principle of protection, they must do everything possible to isolate civilians from the consequences of warfare.
How far can military operations affect civilians?
The law of war accepts that civilians may become “incidental” casualties of military operations. However, the loss of life must not be “excessive in relation to the concrete and direct military advantage anticipated”.
If it can be foreseen that an attack would disproportionately affect civilians, it must not be undertaken.
How can we judge what is proportionate?
Israel argues that civilian deaths must be weighed against the aim of preserving Israel from future Hamas atrocities – justifying a significant level of “incidental” loss of life.
However, the need to comply with humanitarian law, and protect civilians in military operations, cannot be overturned.
Every state will assert in a war that it is fighting for its vital interests. Humanitarian law would lose its meaning if it had to give way to state interests, however legitimate these may be.
Proportionality requires the military value of each operation in a campaign be measured against likely civilian casualties.
Is it a war crime for Hamas to use ‘human shields’?
It is a war crime to use human shields to protect armed forces from attack. However, Hamas’s “unwilling human shields” in densely populated, urban areas must be protected.
The principle of distinction – to target only the enemy – continues to apply, even if this means that Israeli soldiers may face greater risks, having to fight in an urban warfare environment to minimise civilian casualties.
Can Israel attack civilian targets such as hospitals if they are used for military purposes?
“Medical units” – civilian or military – are protected under humanitarian law. They may lose this status if it can be demonstrated that it has been abused, for instance if artillery operates from within their grounds.
Israel asserts that the major remaining hospital in Gaza, Al-Shifa hospital, is used to shield Hamas infrastructure. If it’s proven that a hospital is used for military purposes and may be liable to attack, patients and staff must be given the opportunity to evacuate.
Where this is not possible, for instance if there are no alternative facilities for patients, civilians still have protection. The principle of proportionality applies. An attack is not permissible where civilian casualties would be excessive when measured against the military benefit.
Where the attacking state has destroyed alternative medical facilities, or created a situation where there is no alternative shelter, this rule gains strength. In Gaza, thousands of non-patients are sheltering on hospital grounds.
Is it lawful to demand that an entire civilian population must leave a theatre of operations?
Humanitarian law requires that a combatant warns civilians of impending operations and facilitates their removal from danger zones where possible. Israel has previously warned residents of apartment buildings before bombing them.
Israel argues that much of Northern Gaza is undermined by Hamas tunnels and installations. Hence, virtually all civilian objects would lose civilian status. However, this logic applies only to specific targets, at a tactical level. It cannot be applied to an entire population of about 1 million civilians, with a view to turning Northern Gaza into a free-fire zone.
Israel cannot discharge its obligation of distinction by wishing the civilians away. This places the burden of protection on victims, rather than attackers.
The International Committee of the Red Cross (ICRC) has confirmed that such massive displacement is unlawful. This finding is strengthened by the fact that civilians are displaced from Northern to Southern Gaza, which is under attack and being denied urgently required supplies.
Can Israel isolate Gaza from supplies?
Israel is not entitled to deprive a vulnerable civilian population of 2.3 million, crammed into a small area, necessary supplies for survival.
A small number of trucks allowed to enter Gaza from Egypt does not begin to address this problem. The argument that Hamas has fuel and supplies is irrelevant. Civilians cannot be held responsible for Hamas’s actions – if there is suffering, it must be urgently addressed.
This is an overwhelming humanitarian emergency. The risk of abuse of supplies, for instance by Hamas diverting fuel to its operations, can be addressed through supervision and control by the aid agencies and the UN assisting deliveries.
If Israel captures parts or all of Gaza, the obligation to provide for the population falls on Israel.
Will there be criminal responsibility for war crimes at the end of all this?
War crimes, whether committed by Hamas or by Israel, entail individual criminal responsibility. Any state can pursue grave crimes through its own courts, as happened in Germany and elsewhere after the genocidal war in Bosnia and Herzegovina.
The ICC can try individuals under international law, and is accumulating evidence for possible prosecutions.
It can only mount trials if states surrender individuals into its charge, but this prospect significantly limits future freedom of movement of major offenders.
Is Israel committing genocide, as a UN official has suggested?
Craig Mokhiber, head of the Human Rights Office at UN headquarters in New York, has resigned, claiming that the conflict has reached genocide level.
Genocide requires attacks on a religious, ethnic or linguistic group with the intent to destroy it in whole or in part.
Despite some Israeli politicians’ inflammatory statements, it is difficult to demonstrate such intent – the legal bar is high.
But in addition to the war crime of individual indiscriminate attacks against civilians, the Gaza bombing campaign as a whole would now likely cross the threshold of an equally serious offence, that of crimes against humanity – a widespread, systematic attack on a civilian population in times of peace or war.
Marc Weller is professor of international law and constitutional studies at the University of Cambridge, a former UN senior mediation expert and has served as senior adviser in many international peace negotiations
