What is international humanitarian law and how does it apply to the Israel-Gaza conflict?

The UK has warned its support for Israel "is not unconditional" and that it must follow international humanitarian law.

It comes six months on from the 7 October Hamas attack which sparked the conflict in Gaza, and rising tensions between the two countries after the killings of three British aid workers in an air strike by the Israel Defence Forces (IDF) and the humanitarian crisis in Gaza.

Writing in the Sunday Times, foreign secretary Lord David Cameron said: "Of course our backing is not unconditional: we expect such a proud and successful democracy to abide by international humanitarian law."

Hamas, a UK-designated terrorist organisation, launched attacks on southern Israel on 7 October in which 1,100 people were killed, with 250 captured as hostages, approximately 130 of whom remain in captivity. Israel has retaliated with months of attacks on the Gaza Strip, resulting in the deaths of more than 33,000 Palestinians, according to the territory’s Hamas-run health authority.

What is international humanitarian law?

International humanitarian law applies to armed conflicts and is designed to protect civilians, prevent injury and suffering and damage to the environment.

The International Committee of the Red Cross (ICRC), an organisation that helps people affected by armed conflict and promotes compliance with international humanitarian law, defines it as a "set of rules which seek, for humanitarian reasons, to limit the effects of armed conflict. It protects persons who are not or are no longer participating in the hostilities and restricts the means and methods of warfare."

International humanitarian law is also known as the "law of war" or the "law of armed conflict".

It is contained in the four Geneva Conventions of 1949, which the ICRC points out "nearly every state in the world has agreed to be bound by", as well as the Additional Protocols of 1977.

How does it apply to the Israel-Gaza conflict?

In addition to the impact of Israel's attacks, there is mounting concern about the level of aid getting into Gaza over land, with Cameron warning of an impending famine if restrictions continue.

Cameron has previously said it is "incredibly frustrating" that Israeli prime minister Benjamin Netanyahu was not heeding calls to open more crossing points to allow more UN staff into Gaza and switch on water and electricity. Rishi Sunak has also said the UK had been “straining every sinew” to get aid into Gaza.

The UK itself is also under scrutiny with its arms sales to Israel, with MPs across the political spectrum saying the UK should stop selling weapons for fear of breaching international humanitarian law.

Export licences could not continue to be granted for UK arms heading to Israel if there was a risk weapons could be used in a serious violation of international humanitarian law.

Deputy prime minister Oliver Dowden, appearing on the BBC's Sunday with Laura Kuenssberg programme, refused to answer when asked if it's true the government's legal advice says Israel has broken international humanitarian law.

Meanwhile, in a statement about the conflict last month, the ICRC pleaded with Israel and Hamas to uphold international humanitarian law.

ICRC president Mirjana Spoljaric said: "A steady, robust flow of humanitarian aid to match the needs is only part of the solution. Alleviating the humanitarian catastrophe in Gaza starts with a clear will and measures that safeguard civilian life and human dignity, meaning both sides must conduct their military operations in a way that spares the civilians who are caught in the middle.

"The only way to achieve this is that the parties strictly adhere to international humanitarian law, which means preserving the life, dignity and humanity of all people affected by armed conflict, regardless of which side they are on. It is the line between humanity and barbarity."

Genocide accusation

Since it started its retaliatory attacks in October, Israel has been accused of genocide, defined as "intent to destroy, in whole or in part, a national, ethnical, racial or religious group". Israel has rejected this as baseless.

In January, South Africa asked the International Court of Justice (ICJ) to declare Israel was committing genocide, and to order Israel to stop its military campaign.

The court did not do this, instead issuing a more general order for Israel to make sure it prevents acts of genocide. A final ruling in the ICJ case in The Hague could take years.

Read more

• Lord Cameron dodging scrutiny on Israel arms sales, says David Lammy (PA Media)

• Banning arms sales to Israel would be 'shameful', Boris Johnson says (Sky News)

• Inside President Biden’s pointed phone call with Benjamin Netanyahu (CNN)