One of Israel's main arguments in disputing the findings of the Goldstone Report is that the Geneva Conventions pertaining to the protection of civilians in wartime are outdated because they cannot be applied to the war against terrorism. According to this argument, Israel did its best to observe the key principles underlying international humanitarian law during Operation Cast Lead, but Hamas made it difficult, if not impossible, to do so. The first principle is that of distinction, which requires each side in a military conflict to distinguish between combatants and non-combatants and avoid, as much as possible, harming non-combatants. The second is proportionality, which states that even when one armed force considers attacking a legitimate military target belonging to the enemy, it may only do so if the harm caused to non-combatants is not excessive and disproportionate to the military advantage gained. According to the Israeli government, it was impossible to scrupulously observe these principles because Hamas deliberately and cynically flouted the laws of war. According to a Foreign Ministry report, their violations included using civilian sites as cover for military operations, staging attacks from residential areas and protected sites, using civilian homes and public institutions as bases for operation, misusing medical facilities and ambulances, blending in with civilians and using them as human shields and other alleged crimes. The government maintained that the 1949 Geneva Conventions, which were drafted following World War II, did not countenance the type of warfare conducted by Hamas and other terrorist groups in Gaza and therefore must be amended. There is strong support for the government's position on this matter, but there are also many who maintain that the current laws are sufficient. Former justice minister and Meretz Party leader Yossi Beilin told The Jerusalem Post, "We must make changes in international law to cope with this strange situation. I have not been convinced by those who say that the current system can cope with terrorist warfare." Irit Kahn, former head of the International Section of the State Attorney's Office in the Justice Ministry, called for an international conference of jurists to consider whether current law is appropriate for fighting terrorists. On the other hand, at a conference held in June 2008, six months before Operation Cast Lead, several prominent jurists urged Israel to abide by the rules of international law in its conflict with Hamas. "There are those who say that the existing rules are not suitable for the war against terror," said Col. (Res.) Pnina Sharvit, former head of the International Law Department in the Military Advocate-General's Office. "For one thing, international law conventions did not take into account this type of armed conflict and, therefore, their laws do not address [today's] problems. Or else they say that the moment one party to the conflict does not act in accordance with these rules, the other side is released from its obligation to do so. "However, I say that the rules of international law are also relevant to the fight against terrorism. Furthermore, it won't help to demand that they be changed. It would be impossible to implement these changes and in the long run, they would be harmful." International human rights groups such as Amnesty International and Human Rights Watch appear to have no interest in making changes in the laws of war. HRW legal expert James Ross told the Post that "while international law can always be improved upon, existing international humanitarian law and human rights law are adequate for fighting organizations responsible for terrorism. "Specifically with respect to the laws of war, the real need is to get all parties to armed conflicts, governments and non-state armed groups, to abide by existing laws rather than trying to draft new law."