The intervention by Israeli Attorney General Menachem Mazuz to suspend a plan to restrict electricity supplies to Gaza raises the issue of Israel's rights and responsibilities under international humanitarian law.

Earlier, there were protests from human rights groups, the UN Secretary General Ban Ki-moon - who called the measure "unacceptable" - and the European Union External Affairs Commissioner Benita Ferrero-Waldner, who said: "There should not be collective punishment".

The Israeli attorney general has the right to intervene in any sanctions taken against Gaza and he did approve restrictions on the supply of petrol and diesel fuel there, but the plan to cut electricity needed "more study", he said, to reduce the effect on the civilian population.

He is acting according to a decision taken by the Israeli government itself that measures against Gaza should not cause "a humanitarian crisis."

It agreed on the squeeze on Sunday as part of a strategy to try to reduce the number of rocket attacks from Gaza into Israel.

The concept is to cut the supply of fuel and to limit the supply of electricity if there are rocket attacks. These, Israeli officials say, have totalled 1,826 since the Israeli withdrawal from Gaza in 2005.

Geneva obligations

Israel no longer occupies Gaza with troops. However, it retains control over Gaza's airspace and coastline, and over its own border with the territory. It also controls the flow of goods, including fuel and energy supplies, in and out.

Many still regard it as an occupying power. In a study on the legal aspects of the Israeli-Palestinian conflict for the BBC in 2006, international lawyer Noam Lubell acknowledged this, though he accepted that some of the issues remained "highly debatable".

An occupying power is obliged to follow the 1949 Fourth Geneva Convention, which seeks to protect the civilian population. The Security Council held in 1979 that the Fourth Convention did apply in the territories captured by Israel in 1967.

Israel, however, has never accepted that the convention should formally apply in the occupied territories, arguing that the conventions refer to occupied state sovereign territories. However it has said that it will be bound by their "humanitarian provisions".

Its recent declaration that Gaza is a "hostile entity" and its regular military operations inside Gaza create an obligation on it to respect the 1977 additional protocols to the Fourth Convention, which protect civilian populations in time of conflicts that fall short of war.

Israel has not signed these protocols but there is an expectation internationally that it should respect them.

Israel argues that it is not obliged to help a "hostile" territory beyond whatever is necessary to avoid a humanitarian crisis.

Human Rights Watch rejects this argument: "A mere declaration does not change the facts on the ground that impose on Israel the status and obligations of an occupying power," said Sarah Leah Whitson, director of its Middle East division.

At issue here as well is whether such collective measures do not sufficiently distinguish between civilian and military. Article 48 of the additional protocol would seem to be most relevant in this case: "... The Parties to the conflict shall at all times distinguish between the civilian population and combatants and between civilian objects and military objectives and accordingly shall direct their operations only against military objective."

'Broken promises'

The Israeli argument is that limited sanctions are better than another major military incursion and that its right to self-defence cannot be ignored.

"The reason for our dilemma, " said Lior Ben Dor of the Israeli embassy in London, "is the huge number of Qassam rockets fired at us. We have to defend ourselves.

"After our disengagement, we thought that Gaza would be helped by Arab states. One even promised to build homes for 30,000 people on the old Israeli settlements. But since the Hamas coup, this hasn't happened. Although we are not legally responsible, we don't want the people to starve. We let trucks in every day with food supplies.

"The plan is to use these steps to increase pressure. They are unpleasant but better that than a military operation. We hope in this way they will get the message."

As usual in the Middle East, it is not international law that determines policy. The firing of Qassam rockets at Israeli towns itself is internationally regarded as violating the Geneva Convention prohibition on attacks aimed solely at civilians. That does not stop the rockets. Arguments about whether the Israeli influence over Gaza constitutes a legal occupation are remote to those living there.