Mr. Netanyahu, known as a tough-talking but risk-averse hawk whose political life has been defined by security issues, agreed to a 12-hour pause in the fighting on Saturday, but not, so far, to Mr. Kerry’s broader cease-fire plan.

“When I see him on TV now, I see he is gray, you see he does not like the situation he is in,” said Yossi Verter, a political columnist for the Israeli newspaper Haaretz. “He was always very tough with words and not tough with action — now he is tough with actions, but not so much tough,” Mr. Verter added. “He wants to end it, even though he knows he will pay a price.”…

Michael B. Oren, a former Israeli ambassador to the United States, invoked the Hebrew phrase “Im kvar az kvar,” roughly akin to “in for a dime, in for a dollar.”

“If we’re getting slammed, we might as well go all the way,” Mr. Oren said to sum up the Israeli mood. “One of the big checks on Israel has been the fear of being isolated, the fear of being branded as immoral,” he said. “It’s having the exact opposite impact on policy — rather than being a check, it’s being a catalyst, it’s a motivating factor.”