Israel is hoping to cause long-term damage to Hamas's military infrastructure before agreeing to ceasefire talks, officials say, as the deadly confrontation entered its seventh day Monday.
But it appeared to be in no hurry launch a threatened ground operation as the air force continued to pound Gaza, bringing the Palestinian death toll to 172, and as militants fired barrages of rockets at central Israel, sending thousands running for cover in the country's major cities.
"The Israeli government at this stage is not answering ceasefire efforts because we want to know first that we have taken away Hamas's desire to do this again in another year or six months," Finance Minister Yair Lapid told army radio on Sunday.
"That's not happened yet. When it does, then we'll talk."
So far, the Israeli military campaign has been almost entirely from the air.
"The IDF (military) has hit Gaza very hard, but has not hit Hamas's armed wing hard enough," former military intelligence head Amos Yadlin told army radio, saying that so far, only around 50 of the victims were believed to belong to the Islamist movement.
"Things are moving to another stage in which it will try to exact a very high price from Hamas's armed wing and strengthen both our position in the ceasefire negotiations and our deterrence, as well as hitting Hamas's ability to become stronger after the operation."
Despite the pressure, Hamas has also shown little appetite for a truce, insisting Israel end its "aggression" against Gaza, lift its eight-year blockade and release hundreds of its people jailed in an ongoing crackdown in the West Bank.
- 'Hamas's pain map' -
According to a senior military official, the army is operating according to a so-called "pain map" drawn up after the last major confrontation with Hamas militants in November 2012, that sets out targets most valuable to the Islamist movement.
"This will impair its abilities and force it into a difficult process, as long as possible, of post-war rehabilitation," he told reporters, speaking on condition of anonymity.
"The harder we hit them, the longer and more difficult the (rehabilitation) process, and more effective the deterrence."
Although Israel has massed tanks and troops along the border, confirming its readiness for a ground assault, ministers at a late-night cabinet meeting decided against putting boots on the ground -- at least for now, media reports said.
"A good outcome would be damaging the Hamas infrastructure and its ability to produce rockets," the military source said.
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Following days of intensive air strikes, Israel had managed to hit Hamas sufficiently hard that any ceasefire agreement reached now would likely halt rocket fire for a "very long time," Yadlin said, suggesting Israel had a longer-term goal in mind.
"If the aim is to achieve 'quiet for quiet' and to strengthen deterrence, I think those aims have been reached," he said.
"If the aim is to deal a very heavy blow to Hamas's armed wing and damage its future ability to recover and become strong again... there is no doubt that the army must continue this campaign."
- Truce in waiting -
Israel was holding mediation efforts at bay.
"We are not addressing any (truce) offer," an Israeli official said.
"The goal of Operation Protective Edge was and remains to return the quiet to Israel for a long period, while dealing a significant blow to Hamas and other terror groups in the Gaza Strip.
"This goal will be reached either militarily or diplomatically."
Informed Israeli officials played down Egypt's part in any attempts to bring about a ceasefire, despite Cairo's traditional role as mediator in previous truce agreements between Israel and Hamas.
"Right now the Egyptians are in the picture but they are somewhat reluctant to play a practical role given their own internal challenges," former peace negotiator Michael Herzog told reporters, noting the bitter relationship between the current Cairo government and Hamas.
Speaking to AFP, an Israeli official described Egyptian involvement until now as "lame".
Although Israel appeared happy to keep truce efforts at arm's length, it appeared in no hurry to launch a ground operation, commentators said.
"Despite the convoy of tanks heading south and the infantry brigades massing near the border with Gaza, it is obvious that Israel is in no hurry for the operation’s ground phase," Amos Harel wrote in Haaretz newspaper.
So far, although more than 750 rockets have struck Israel and another 200 have been shot down, no Israelis have been killed and a handful badly injured.
But a ground operation would likely change that, with militants also seeking to use the opportunity to capture soldiers to use as bargaining chips, as happened with Gilad Shalit -- a soldier held in Gaza for five years whose freedom was bought with the release of over 1,000 Palestinian prisoners.
"We see (Hamas) as seeking ways to carry out an attack that would be a victory picture as well as a bargaining chip," the military source said.