“The tragedy is the failure of these two to get over their grudges and the bad blood and work in an intimate, serious way together,” said Ari Shavit, a columnist for the left-leaning newspaper Haaretz. “Rather than the great democracy and the small democracy working together, they seem to be working with deep suspicion of each other.”

The critical difference between the American and Israeli views of the situation has long been one of timing. In Jerusalem, the clocks are ticking — and, as a senior government official put it, “all of them are now ticking at a higher speed.”

“Every week they get closer,” this official said of Iran, speaking on the condition of anonymity because he, too, is involved in the high-level deliberations. “While our side can, every week, seem to be in the same place, their side every week gets closer to this target.” (Iran contends its nuclear work is for peaceful purposes.)

Though Mr. Netanyahu and Defense Minister Ehud Barak are crucial to making the final call, attention has turned to a group of 14 ministers known as the inner cabinet, or security cabinet. Yossi Melman, an author of “Spies Against Armageddon,” a history of Israeli intelligence, said military actions typically required “a solid majority” of 12 or 13 members of this group, which is currently divided.

Three or four of the ministers are believed to be opposed to an independent Israeli strike, while six seem to be in favor. Two big unknowns are Deputy Prime Minister Moshe Yaalon and Foreign Minister Avigdor Lieberman, who both declined to be interviewed.

Mr. Netanyahu has been wooing Mr. Yaalon, including him in a small dinner when Secretary of State Hillary Rodham Clinton was here in July. In a recent Twitter post, Mr. Yaalon warned, “History will judge whether the U.S. faced up to the Shiite threat in time to prevent Iran from acquiring a military nuclear capability.” But further posts indicated some wiggle room: “Anyone who wants to prevent the exercise of military power must see that additional biting sanctions are applied,” he wrote.

Mr. Lieberman, who frequently diverges from Mr. Netanyahu, said on television last week, “There is no situation in which Israel can accept a nuclear Iran.”