In a little-noticed exchange Tuesday at the Senate Armed Services Committee, a top US general said he had no doubt Israel would attack Iran if the Islamic Republic reached a critical point in its nuclear weapons drive. Furthermore, said General James Mattis, Israel could so without the assistance of the United States.

Mattis, who is retiring this month as head of the US army’s Central Command, which includes the Middle East and North Africa, was responding to questions from Sen. Lindsey Graham, who asked him whether he believed Israel would strike at Iran if the regime “reached a critical point in terms of nuclear capability.”

Responded Mattis: “The Israelis have said so; I take them at their word.”

Graham followed up by asking whether Israel would need US assistance to carry out such an attack. Said Mattis, “They could conduct a strike without our help.”

Asked next whether the US should assist in such an Israeli attack, Mattis said, “That would depend on what the objective of the strike is. Is it to stop them, is it to delay them, is it how long do you want to delay them, is there a broader effort…?”

Last summer, the chairman of the US Joint Chiefs of Staff, Gen. Martin Dempsey, said he would not want to be “complicit” in an Israeli strike on Iran, which could undo US-led international pressure on Iran if carried out prematurely.

Graham then asked the general what kind of US attack he would recommend — a limited strike or one that targeted Iran’s navy, air force and Revolutionary Guard. Mattis said that “I owe confidentiality to the president” on that question.

Finally, Graham asked him whether a nuclear Iran would lead other regional states to seek similar nuclear capabilities. Mattis said he had been told by “the leadership” of at least one Sunni state that they would indeed pursue a nuclear capability in such a case, and he believed other states would too.

In the same session, Mattis said flatly that sanctions were not preventing Iran’s nuclear progress, adding that he had prepared a military option for the president.

A simple “No, sir” was Mattis’s response when asked whether “the current diplomatic and economic efforts to stop Iran from obtaining nuclear capability” were working.

He said the regime in Iran knows “it can’t win the affection of its own people,” was concerned sanctions could turn its people against it, and might be prepared to even give up its nuclear effort if it feared its survival in power was at stake. “I think we have to continue sanctions, but have other options ready.”

Mattis said Iran could be convinced to alter its course by “a purely cost-benefit ratio,” but at the moment, he noted, the “nuclear industry continues” apace, despite sanctions.

“Between economic sanctions, diplomatic isolation, and encouragement of behavior that does not cost them such a degree of political support that they end up losing power, there may yet be a way to bring them to their senses,” the general stated.

Such means to bring Iran “to its knees,” Mattis commented in response to another question, did not necessarily entail “open conflict,” but a military operation is “one of the options that I have to have prepared for the president.”

Mattis’s statements came in the wake of a fresh effort on the part of the West to curb Iran’s nuclear program via diplomatic means, and echoed comments made by Prime Minister Benjamin Netanyahu on Monday.

“We have to stop Iran’s nuclear enrichment program before it’s too late. Words alone will not stop Iran. Sanctions alone will not stop Iran. Sanctions must be coupled with a clear and credible military threat if sanctions fail,” Netanyahu told a room of some 13,000 AIPAC supporters in Washington by satellite feed from Jerusalem.

In an earlier speech, US Vice President Biden told the same crowd that President Barack Obama isn’t bluffing when he says he’ll use military action, if ultimately necessary, to prevent Iran from acquiring a nuclear weapon.

An Iranian spokesman on Tuesday said the country’s nuclear talks with world powers yielded “positive results” and assailed what he described as “negative” remarks by some Western officials following those negotiations.

According to Ramin Mehmanparast, the Foreign Ministry spokesman, some Western officials and media outlets are trying to portray the results of the talks last week in Almaty, Kazakhstan, in a bad light because of their own political agenda.

“It is a matter of surprise that some Western and regional countries, as well as their media outlets, are trying to cast a negative image on the talks, which had positive conclusions,” said Mehmanparast.

The Associated Press contributed to this report.