Israel has said the aim of the past three days of intense bombing in Gaza is to stop rockets being fired by Palestinian militants into southern Israeli towns.

The rockets have claimed 19 lives in the past eight years, but have become an increasingly serious problem for the Israeli government.

To reduce the rocket fire, Israeli military analysts argue, is a modest goal. However, even within Israel there remain sharp differences of opinion about how to achieve that. Most believe the latest conflict will eventually end with a new lull in the fighting, or at best another short-term ceasefire agreement - the latest in a long line of temporary ceasefires in the conflict between Israel and militants in Gaza.

Although Israel has put in place some preparations for a ground invasion, including preparing a call-up of reserves and deploying tanks near the Gaza border, that is still not seen as an inevitable step.

Shlomo Brom, a retired Israeli general and a military analyst at the Institute for National Strategic Studies in Tel Aviv, said the point of the conflict was for Israel to exact the best conditions for a future ceasefire with Hamas, the Islamist movement which controls Gaza after winning Palestinian elections three years ago.

"The military operation is changing the dynamic, making it clear to Hamas that it is going to pay a very high cost for violations of the ceasefire," Brom said. "I think Hamas deluded itself by thinking Israel is kind of paralysed because of its political system or the possible reaction of its population to some suffering."

For nearly six months Israel and Hamas held a ceasefire in Gaza, although it broke down in the final weeks with violations on both sides. Now both Hamas and some Israeli leaders have said they are not willing to return to a ceasefire deal.

Ehud Barak, Israel's defence minister, told Fox News on Saturday when the bombing began: "For us to be asked to have a ceasefire with Hamas is like asking you [the US] to have a ceasefire with al-Qaida."

The reality is that a new ceasefire agreement is probably the best Israel could hope to achieve. As Alex Fishman, a columnist on the Yedioth Ahronoth newspaper, put it bluntly yesterday: "The answer to the question of what we want is simple: To stop the fire. In order to stop the fire, we have to reach an arrangement, and in order to persuade Hamas to reach an arrangement, we are now breaking its bones - among other reasons, so that the price it demands will not be high. But we have not yet decided, amongst ourselves, what price we are willing to pay."

Yet there are others who raise broader questions about Israel's policy towards Gaza, particularly in the last three years since Hamas won the electoral victory.

Yossi Alpher, a former official at Mossad and a military commentator, agreed that Israel was seeking a ceasefire on more acceptable terms. But he was critical of the tough economic blockade Israel has imposed on the Gaza Strip in recent years, limiting imports to humanitarian supplies and preventing all exports, a policy that has all but wiped out private industry and brought Gaza's economy to collapse. "The economic siege of Gaza has not produced any of the desired political results," he said. "It has not manipulated Palestinians into hating Hamas, but has probably been counter-productive. It is just useless collective punishment."

He said that in future Israel would have to choose either to recognise Hamas was around to stay and to talk to the movement, however unpalatable that might be for most Israelis, or to fully reoccupy the Gaza Strip, topple Hamas and bear all the costs involved.

Some have even spoken publicly against the current bombing in Gaza. Tom Segev, one of Israel's most respected historians, has been particularly critical, arguing that the premise of bombing to secure a peace agreement was false.

"Israel has also always believed that causing suffering to Palestinian civilians would make them rebel against their national leaders. This assumption has proven wrong over and over," Segev wrote in yesterday's Ha'aretz newspaper. "Since the dawn of the Zionist presence in the land of Israel, no military operation has ever advanced dialogue with the Palestinians."