JERUSALEM - As Israeli troops once again operated inside the Gaza Strip on Friday, the risks of a deep entanglement, a failure to curb the rocket fire, and the condemnation of civilian casualties were all too apparent.
Twice before, Israel has battled Hamas, the Palestinian militant group that dominates Gaza, and twice before, Israel has halted under international pressure without eliminating the threat of rocket fire.
But this time, officials and analysts say, the landscape is different. Israel has publicly framed a clear agenda targeting tunnels it says militants built to store weapons or stage attacks on its territory. This time, a weakened Hamas cannot turn to Egypt for respite. This time, Western leaders appear more patient: President Barack Obama expressed concern Friday about "the loss of more innocent life" but also said no nation should be subjected to a hail of rockets or underground incursions.
The start of the ground campaign was a stark contrast to Israel's 2009 invasion, when forces quickly bisected the tiny coastal enclave and blockaded Gaza City, where they engaged in gunbattles with Hamas fighters. On Friday, the troops operated mainly in farmland within about a mile of Gaza's northern, southern and eastern edges, and quickly announced they had uncovered more than 20 tunnel exit points.
Setting the bar relatively low helps hold back public expectations, provide the military with achievable goals, and build international legitimacy. It also reflects Israel's reluctance to re-engage long-term in Gaza or rout Hamas only to find it replaced by even more radical groups, though on Friday Prime Minister Benjamin Netanyahu ordered the military to "prepare for the possibility of widening, significantly," its offensive.
But if the action on the ground has changed from past conflicts, so has the diplomatic horizon. Analysts said that political shifts among Palestinians and across the region had made the familiar paths to cease-fire agreements harder to find this time.
Hamas, financially desperate and politically isolated but rich in armaments, is desperate to score points with the public either by harming Israelis or curbing what it calls the siege that has plunged Gaza into economic and humanitarian disaster. Israel, under pressure internationally for expanding settlements in the West Bank and for the number of civilians killed, including some 65 children, in the 11-day assault on Gaza, wants mainly to disarm the militants.
"There's a certain contradiction here," said Itamar Rabinovich, a former Israeli diplomat and university president. "That's what you need mediators for - you find that magic formula, constructive ambiguity, that enables both parties to claim achievement.
"Right now, those actors are not there."
Washington, which has helped broker previous cease-fires, is consumed with other crises, and has diminished credibility in the Middle East. Egypt, which during the brief presidency of Mohammed Morsi strongly supported Hamas, now treats the group as an enemy, and is loath to let its rivals Qatar and Turkey play a significant diplomatic role to aide residents of Gaza.
That leaves President Mahmoud Abbas of the Palestinian Authority, an adversary of both Israel and Hamas, as the primary Palestinian interlocutor. Weak at home but increasingly active on the international stage, he shuttled from Cairo to Istanbul on Friday for what were described as cease-fire negotiations.
"The fact that Abbas is involved this time, unlike all previous cases, could mean something," said Khalil Shikaki, a Palestinian pollster and analyst. "He does not have a lot of leverage here, but the little he has might allow for a three-way deal - Hamas, Abbas and the Israelis. That's the way things might be smoother than to wait for the battlefield itself to determine the outcome, which could take a very, very long time, and a great deal of bloodshed."
The bloodshed continued Friday as an artillery shell killed three children of Ismail Abu Musalam in their bedroom near the northern entry to Gaza around noon - the third day in a row in which groups of youths were killed - and another shell killed eight members of the Abu Jarad family, four of them children, at night. The Palestinian death toll topped 280, plus 2,000 wounded, as airstrikes continued over the relatively contained ground operations.
The Israeli military said it uncovered 10 distinct tunnels, struck 240 targets, killed 17 militants and detained 21 others for questioning on the first day of the ground operation. A 20-year-old soldier, Eitan Barak, was shot and killed in the early hours - the second Israeli death of the war; seven soldiers were injured.
Sirens signaling rockets from Gaza sounded all day and night throughout southern and central Israel - one of several over Tel Aviv sounded during Obama's phone conversation with Netanyahu. The Israeli military counted 135 rockets in the first 24 hours of the ground operation, 40 of them blocked from hitting cities by the Iron Dome defense system. One damaged an empty kindergarten and a synagogue.
Netanyahu - who had won plaudits from the waning Israeli left this week for embracing an Egyptian cease-fire proposal, agreeing to a United Nations request for a humanitarian pause, and not invading Gaza sooner - expressed regret Friday "for every mistaken strike on civilians." But he also said he was engaged in "unending" diplomacy to create "the international space" so Israel could "act systematically and with power against a murderous terrorist organization and its partners."
International reaction fell mainly along predictable allegiances to Israel and the Palestinians, but there was some movement on the margins. Analysts attributed that to the battle's roots in last month's abduction and murder of three Israeli teenagers, to Hamas' dwindling roster of friends, to Israel's quick embrace of Egypt's cease-fire proposals, and to the mission's modest stated goals.
Obama reaffirmed his "strong support for Israel's right to defend itself," suggesting it was based on his understanding that "the current military ground operations are designed to deal with the tunnels." Prime Minister Recep Tayyip Erdogan of Turkey accused Israel of "committing genocide," raising further questions about his ability to play any kind of constructive role.
In Europe, concern over casualties was mixed with a commitment to Israel's right to self-defense. U.N. Secretary-General Ban Ki-moon announced he would travel to Israel on Saturday to express solidarity with people on both sides and try to mediate.
"Israel has legitimate security concerns, and we condemn the indiscriminate rocket fire," Jeffrey Feltman, the U.N. undersecretary-general for political affairs, said at an emergency session of the Security Council. He added, however, "we are alarmed by Israel's heavy response."
Einat Wilf, a former center-left member of Israel's Parliament, said world leaders who had generally focused on Netanyahu's "hawkish positions" had seen him be "very prudent" so far. "There's one thing that's really clear for me is that on the Israeli side there's incredible reluctance to enter into anything large-scale," Wilf said. "I think this is one of the reasons we're getting substantial backing; there is a sense that there's no trigger-happy person at the helm, quite the contrary."
Yaakov Amidror, Netanyahu's former national security adviser, said the prime minister's approach had "cost him with his own constituency - the majority of it do not like cease-fires in such occasions" - but that for now the government seemed to be ignoring calls for retaking Gaza.
"This operation is very limited geographically," Amidror said. "Most of the operation will not take place in crowded areas with a lot of population, but areas used for agriculture. The land operation, it's very easy to see where it will be finished. If nothing bad will happen, we will identify the locations of the tunnels, we will blow them up, and we will retreat."
But he added, "How to finish the whole operation in terms of stopping the rockets and the missiles, this is much more complicated."