Since the end of hostilities in Lebanon, human rights organizations have been collecting evidence to bring war crimes charges against various Israeli officials. Could Israelis be tried for war crimes and crimes against humanity?
In today's world there are three mediums were such cases could be brought: the International Criminal Court (ICC), ad hoc UN tribunals (such as those used to prosecute Milosevic and Rwandan leaders), and European countries which recognize that war crimes and crimes against humanity are under universal jurisdiction, which means that any country could try those cases.
Israel is not a signatory to the Rome Statute of the ICC, and therefore none of its nationals could be tried in the court unless they committed the crime in the territory of a state which did ratify the treaty (Article 12(2)(a-b). Lebanon is not a signatory, so the ICC, by its own terms, cannot execute jurisdiction over any Israeli citizens.
Ad hoc tribunals could be created under Chapter VII of the UN Charter but have gone out of vogue now that the ICC is in operation. Plus, the US would undoubtedly veto the creation of any such tribunal, even if opponents of Israel could get the rest of the Security Council to agree.
Countries that consider war crimes to fall under universal jurisdiction are the best forums to bring these claims. It's interesting to note that Israel, in the Eichman trial, was one of the first countries to assert universal jurisdiction, so no one can claim that universal jurisdiction is a liberal European creation.
Belgium became famous after its problems relating to the prosecution of Ariel Sharon in 2003, and its subsequent amendment to the universal jurisdiction law that cut back on the scope of that jurisdiction. The case became moot once the law was amended to limit its application to crimes committed subsequent to the enactment of the universal jurisdiction law. The court also dismissed the case based on the idea of diplomatic immunity, which immunizes a sitting head of government (or state) from prosecution. Belgian diplomats understood the political ramifications of an unbridled universal jurisdiction law, and quietly put the extensive conception of the law to sleep.
However, even with the amendments Belgium still allows prosecutions of officials who do not have immunity in cases where the alleged crime occurred subsequent to the law's enactment. Moreover, other countries have similar laws. So could Israeli generals, or even Amir Peretz, be tried in England or Belgium?
In theory probably. In practice it's unlikely (to say the least) that an Israeli general will tried in England, a country which is currently fighting a war in ways that I'm sure are not pristine by human rights advocates' standards. Furthermore the political fallout from trying a high ranking Israeli official in a European country is probably too great for any country to shoulder.
In 2005 Doron Almog refused to step off an El Al plane after he was tipped off of his impending arrest. In my mind, if Almog was arrested, England would probably have pardoned or released him in a similar way or possibly even modified their law, as Belgium did in 2003. It's hard to imagine a democratic country trying a fellow democracy's generals for crimes they didn't commit against the former's citizens or in its territory.
In practice universal jurisdiction laws only work against dictators and weak countries. The political ramifications of trying former Congo leaders are minimal, so the country is willing to prosecute. But trying a general of a first world democracy with an extremely powerful backer is a whole different ballgame and could lead to a game of tit for tat. None of that is in Belgium or England's best interests.