LONDON (Reuters) - Israel will be compelled to attack Iran’s nuclear sites if Western powers cannot agree crippling sanctions against Tehran by the end of the year, a former Israeli deputy defense minister said on Wednesday. Ephraim Sneh, who holds no position in the current Israeli government and was speaking in his personal capacity, told Reuters it was not clear the United States and European Union had the decisiveness to take such steps, which should include tougher banking and oil curbs, by year’s end.

“We cannot live under the shadow of an Iran with nuclear weapons,” he said in an interview on a visit to Britain. “By the end of the year, if there is no agreement on crippling sanctions aimed at this regime, we will have no choice.”

“This is the very, very last resort. But ironically it is our best friends and allies who are pushing us into a corner where we would have no option but to do it.”

“I wonder if they will do it (a tougher sanctions regime) quickly enough. If not, we are compelled to take action.”

Sneh, a retired brigadier-general, is a former member of parliament’s defense and intelligence committees. As deputy defense minister, he held responsibility for Iran.

A “BLOODLESS” STRATEGY

Sneh’s visit was facilitated by The Israel Project, a privately-funded media organization that seeks to explain Israel’s security position in the region and has arranged news conferences for serving Israeli officials overseas.

The United States, Germany, France and Britain have threatened Iran with a fourth round of U.N. sanctions if it continues enriching uranium and refuses to clear up concerns it has done extensive research into how to build a nuclear weapon.

Iran says the activity is a civilian electricity program.

Israel has said a nuclear-armed Iran would be a threat to its existence and points to Iranian President Mahmoud Ahmadinejad’s calls for Israel to be wiped off the map.

That has raised worries that Israel could ultimately carry out a military strike against Iranian nuclear sites.

Sneh said the sanctions should consist of a total Western boycott of the Iranian banking system, a ban on selling Iran refined petroleum products, a ban on selling spare parts to the Iranian energy industry and a ban on senior Iranian officials traveling to Western capitals.

Sneh said the sanctions need be imposed only by the United States and European nations, because it was clear Russia and China would not go along with them and in any case the need for the involvement of “Russia and China is a myth.” Imposed by the West, such a strategy would be tough enough to work.

“It is bloodless, and it even stops short of a naval blockade,” he said.

In comments that appeared to signal Israel had not given up on international diplomacy to curb Tehran’s atomic ambitions, Prime Minister Benjamin Netanyahu said on Monday the time had come for tougher sanctions on Iran over its nuclear program.

Sneh said Israel had many reasons to block the emergence of a nuclear weapons-capable Iran, because in that event

-- Immigration to Israel would stop.

-- More able young men and women would emigrate to pursue their future in places seen as more secure.

-- Investment in Israel would be reduced.

-- Decision-making by the cabinet would be hostage to the fear of Iranian nuclear retaliation. The processes of government would thereby be “substantially distorted.”

-- Extremist forces in the Middle East would be empowered.

-- Iran would pressure moderate forces in the region to toughen their positions in contacts or negotiations with Israel, for example in discussions over Jerusalem or the Golan Heights

-- Saudi Arabia and Egypt would seek to obtain nuclear weapons themselves, bringing about a Middle East “fully loaded with nuclear weapons.”