Donald Macintyre: Whatever else happens, this represents a massive shake-up in the conflict

The prisoner swap foreshadowed in the deal approved by Israel's Cabinet last night is a huge shake of the kaleidoscope through which the Israeli-Palestinian conflict has long been viewed. For the majority of Israelis, including the parents of Gilad Shalit, the return of the young soldier after his five-year ordeal will be a cause of unalloyed celebration. So too – assuming the deal is realised as proposed – will it be for hundreds of families of Palestinian prisoners. But in terms of raw politics, its effect will be no less dramatic.

Benjamin Netanyahu observed last night that there had been an "inherent tension between the desire to return an abducted soldier and the maintaining of Israel's security". This was a barely-veiled acknowledgement that for a significant portion of Israel's political hard right, including in his own party, the release of so many political prisoners was too high a price even for the freeing of a young conscript, one most Israeli parents are well aware might have been their own son or daughter.

The fact remains that Mr Netanyahu has succeeded in doing what his predecessor, Ehud Olmert, on whose watch the soldier was taken, failed to do. It is too early to say the release of Gilad Shalit, assuming it goes ahead without another hitch, will win Mr Netanyahu the next election. But it can hardly fail to strengthen a politician who had been beset by increasingly impatient criticism abroad and a welter of social protest at home.

There are deep ironies in the fact that a right wing Israeli Prime Minister whose government reacted with outrage to an entirely peaceful approach to the UN by the moderate Palestinian President, Mahmoud Abbas, has now concluded such a deal with a faction it has long condemned as no more than a terrorist organisation.

Many in Fatah will be angered that Hamas's violent seizure of Sgt Shalit has been rewarded with the kind of large scale, heavy-duty prisoner releases that Mr Abbas was unable to secure through peaceful negotiations. All the more so if the freed prisoners do not include Marwan Barghouti, long one of Fatah's most charismatic figures.

The accord between Israel and Hamas could presage others, perhaps a durable ceasefire in Hamas-controlled Gaza and perhaps the further easing of the long siege of the territory. For that and many other reasons, including the human ones, the deal is welcome. The paradox is that, in the short term, the political beneficiaries are likely to be one of the most right wing governments in Israel's history and an Islamic faction it has long regarded as one of its greatest enemies.