A special envoy from the British government came to Israel in secret about two weeks ago for talks with Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak.

According to an Israeli source who asked to remain anonymous due to the sensitivity of the matter, the high-ranking visitor delivered a stern message from British Prime Minister David Cameron against an uncoordinated Israeli strike on Iran at this time.

The Israeli source related that British fears about an imminent Israeli decision to strike Iranian nuclear facilities was further heightened by Netanyahu's failure, during a phone conversation between the two leaders prior to the Olympics in July, to provide clear and precise answers to Cameron's questions about Israel's intentions on the Iranian front.

During his visit the British envoy met with a number of Israeli security and diplomatic officials and stressed that Britain believes there is still time for diplomatic measures to work, and that the economic and diplomatic sanctions against Iran should be continued and perhaps heightened.

Officials in the British embassy in Israel refused to comment on the issue, as did officials in the Prime Minister's Office in Jerusalem.

Israel and Britain cooperate closely on the Iran issue in the intelligence and diplomatic spheres, and Britain briefed Israel in full on the negotiations between the six world powers and Iran. Britain also includes Israel in its efforts to impose additional sanctions on Iran. London supports keeping up the economic and diplomatic pressure on Iran while employing covert means to delay Tehran's nuclear program.

According to the Israeli source, the firm message of the U.K. envoy, together with the phone conversation during the same period between Netanyahu and German Chancellor Angela Merkel and public remarks by high-ranking U.S. officials in recent weeks have affected Netanyahu's and Barak's attitude to the Iran issue.

The combined weight of the messages coming from Western powers seems to have cooled the two men's enthusiasm for launching an uncoordinated attack on Iran. Netanyahu, and to a greater extent Barak, have apparently recognized that in addition to the military implications of such a move missile barrages that could kill hundreds of Israeli civilians - it would also have serious foreign-policy implications, in the form of a very deep rift with Israel's greatest allies: France, Britain, Germany and the United States.

In the past two weeks, in the wake of the Western messages, Netanyahu has changed tack and began talking about the need to set "red lines" for Iran over its nuclear program in order to head off a military confrontation.

Ideally, he would like to present at least some of his proposals for new understandings on the issue to President Barack Obama during the UN General Assembly in New York later this month. In fact the leaders' visits to the city will not overlap, and in any event Obama seems none too eager to chat with Netanyahu these days.

Speaking to reporters in Washington, State Department spokeswoman Victoria Nuland said, "It is not useful to be ... setting deadlines one way or another" or to outline "red lines" for how far the U.S. can allow Iran's nuclear program to advance.

She repeated that President Barack Obama has stated unequivocally that the United States will not allow Iran to obtain a nuclear weapon, and that U.S. support for Israel's security is unwavering.

But she said she would not speak about ongoing discussions between the U.S. and Israel, calling such talk "not helpful for the diplomacy."

U.S. Secretary of State Hillary Clinton also said the administration is not prepared to make such a public commitment.

"We're not setting deadlines," Clinton said in an interview with Bloomberg Radio.

On Sunday, Netanyahu said Jerusalem and Washington were talking about pressuring Iran further. He said setting clear red lines that if crossed will prompt a military strike against Iran's nuclear facilities is the only way war can be avoided.

Clinton demurred, saying negotiations were "by far the best approach" to prevent Iran from developing nuclear weapons.

"We're watching very carefully about what they do, because it's always been more about their actions than their words," she said on the sidelines of an Asia-Pacific forum in Vladivostok, Russia.

Clinton emphasized that while Israel and the United States share the goal of preventing Iran from developing a nuclear weapon, they disagree over the negotiations timetable with the Islamic Republic. Israel is "more anxious about a quick response because they feel that they're right in the bull's-eye, so to speak," Clinton said, adding, "But we're convinced that we have more time to focus on these sanctions, to do everything we can to bring Iran to a good-faith negotiation."

Israeli officials were dismayed by Clinton's comments rebuffing Netanyahu's demand for "red lines."

"Such remarks won't stop Iran's centrifuges, just the opposite," one senior official in Jerusalem said, adding, "Without a clear, firm red line Iran won't stop its race to a nuclear weapon. Statements like these not only do not deter Iran, they reassure it," he said.