Then there is the alternative basis for empowering the ICC prosecutor: a state party to the ICC treaty (and there are presently 122) may require the prosecutor to investigate international crimes committed on its territory or by its people. Israel has refused to ratify the treaty, thereby depriving itself of a means to hold Hamas to account for rocket attacks and leaving the territory of Gaza (which it dubiously claims not to ''occupy'') an open question. Can the State of Palestine, were it to ratify the treaty, invoke an ICC investigation into war crimes in Gaza? In 2009 it attempted to do just that in seeking a remedy for ''Operation Cast Lead'', but the prosecutor refused to accept that it was enough of a state to be entitled to become a party to the treaty. However, in November 2012 the General Assembly accorded Palestine the status of statehood – as a non-member observer state, but a state nonetheless. It has since been permitted to become a state party to 13 international treaties. Might it now – today – accede to the ICC treaty and with the appropriate declarations under that treaty invite the prosecutor to investigate war crimes committed in the territory of Gaza since November 29, 2012?

It might. But why has it not done so already, or over the past 18 months? Because of the pressure brought to bear on President Mahmoud Abbas to refrain from doing so – most heavily from the US but also from Britain and France, whose diplomats claim that any prosecutions of either party for war crimes would undermine peace negotiations. This is nonsense, as all but diplomats must by now realise – their efforts over past decades have come to nought and the blood hatred reignited by the present war will scupper peace for the foreseeable future. Unless, and just possibly, some form of justice process is permitted to begin.

There is no alternative. The Human Rights Council (a body that tilts against Israel) promises to set up an independent inquiry but we have been there before. After Operation Cast Lead, its Goldstone enquiry castigated both sides. But its chairman then retracted the central finding (that Israel had a policy of targeting civilians) and its impact was weakened. There were no prosecutions of Hamas commanders, of course, and although Israel investigated allegations against 400 soldiers, just two were brought to trial; and the only prison sentence – of seven months – was imposed on a soldier for stealing a credit card.

The advantage of an ICC referral is that it would provide a strong incentive to both sides to punish their own criminals effectively, so as to forestall their indictment in The Hague. By bringing military leaders and the politicians who approve their conduct within the ''command responsibility'' net, there will be a disincentive to the commission of further crimes in the course of this ongoing conflict. Indictments, by spelling out particulars of the charges, will clarify that, for example, deliberately storing rockets in or near a school or hospital is a war crime, as is a decision to bomb that school or hospital in the knowledge that civilians are taking shelter there. Of course, there is a ''catch as catch can'' quality about international justice, as trials can only be held when alleged perpetrators are caught. But this can happen – after 17 years in the case of General Ratko Mladic – and even to heads of state.

There is also the need for new precedents in the law of war to limit the behaviour of modern army behemoths. The most wicked use of military might – ''Operation Searchlight'', conducted by depraved Pakistani generals in Dhaka in 1971 – has gone unpunished, although a few of its perpetrators are still alive. Everyone is wittering on about ''the law of proportionality'' but few understand it. Obviously it is ''disproportionate'' if 1400 (mainly civilians) are killed on one side, as against 50 soldiers on the other. But in war law the issue is defined as whether ''collateral damage'' to civilians by an attack on a military target (eg, a school where rockets are stored) is ''excessive in relation to the concrete and direct military advantage anticipated''. This allows commanders to think they can get away with shelling the school because the destruction of the rockets gives their side a concrete advantage. A court conviction would bring home to them that no ''military advantage'' can ever justify the mass murder of children.