But behind the scenes, the White House decided to keep certain allies under close watch, current and former U.S. officials said. Topping the list was Israeli Prime Minister Benjamin Netanyahu.

The U.S., pursuing a nuclear arms agreement with Iran at the time, captured communications between Netanyahu and his aides that inflamed mistrust between the two countries and planted a political minefield at home when Netanyahu later took his campaign against the deal to Capitol Hill.

The National Security Agency’s targeting of Israeli leaders and officials also swept up the contents of some of their private conversations with U.S. lawmakers and American-Jewish groups. That raised fears — an “Oh-s— moment,” one senior U.S. official said — that the executive branch would be accused of spying on Congress.

White House officials believed the intercepted information could be valuable to counter Netanyahu’s campaign. They also recognized that asking for it was politically risky. So, wary of a paper trail stemming from a request, the White House let the NSA decide what to share and what to withhold, officials said. “We didn’t say, ‘Do it,’ ” a senior U.S. official said. “We didn’t say, ‘Don’t do it.’ ”

Stepped-up NSA eavesdropping revealed to the White House how Netanyahu and his advisers had leaked details of the U.S.-Iran negotiations — learned through Israeli spying operations — to undermine the talks; coordinated talking points with Jewish-American groups against the deal; and asked undecided lawmakers what it would take to win their votes, according to current and former officials familiar with the intercepts.

This account, stretching over two terms of the Obama administration, is based on interviews with more than two dozen current and former U.S. intelligence and administration officials and reveals for the first time the extent of American spying on the Israeli prime minister.

An expanded version of this report appears on WSJ.com.

Israel Will Submit Official Protest If Reports Of US Spying Are True

By i24news

December 30, 2015 "Information Clearing House" - "i24news" - White House does not deny the Wall Street Journal's report that US spied on Netanyahu

Israel's Intelligence Minister reacted Wednesday to claims by the Wall Street Journal that the White House authorized monitoring of Prime Minister's Benjamin Netanyahu's communications and that Israel had attempted to spy on the US.

"Israel does not spy in the US and we expect the same from our great friend. If the reports turn out to be true, Israel must submit and official protest to the US and demand to cease such activity," said Intelligence Minister Yisrael Katz.

Contacted by AFP, the White House did not deny the Wall Street Journal's report, which cites several serving and former US officials, but stressed the importance of its ongoing close ties with Israel.

Fearing Israeli Prime Minister Benjamin Netanyahu was working to derail the nuclear deal with Iran, the White House authorized the National Security Agency to monitor the leader's communications, the Wall Street Journal reported Tuesday.

This appears to undermine Obama's declaration – made following the 2013 scandal over the scale of NSA's surveillance, disclosed by its former contractor Edward Snowden – that the US would no longer spy on heads of friendly states.

The report detailing the minutiae of NSA's snooping and once more propelling into the spotlight Washington's mistrust of the hawkish Israeli premier could usher in a new crisis in the already tense relations between Netanyahu and President Barack Obama's administration.

According to the publication, NSA's "targeting of Israeli leaders and officials also swept up the contents of some of their private conversations with US lawmakers and American-Jewish groups."

This is a particularly sensitive issue as not only are members of Congress a constitutionally troublesome target for a spying agency which primarily examines foreign targets, but it is problematic if the executive branch of government is perceived to be spying on the legislative branch.

Yet it is understood that while some allies, such as German and French heads of states, have become "off limits" for NSA snooping, others, such as Netanyahu and Turkey President Recep Tayyip Erdoğan, remained targets of intensive monitoring.

While Washington officials were wary of giving the agency direct and specific orders, fearing the paper trail this would leave, the report quotes Obama as saying "privately" that spying on Netanyahu serves a “compelling national security purpose”.

Netanyahu and Obama have a notoriously testy relationship, clashing over Israeli settlement building and the Middle East peace process. However it was the divergence on how to deal with the Islamic Republic's unsanctioned nuclear program that compelled US to ramp up its surveillance in 2011, when Washington officials feared Israel might attack Iran's nuclear installations without warning.

According to the report, the Obama administration was at that time pursuing secret talks with Tehran, anxious that this news did not leak. This is why, according to WSJ, the US kept intercepting Netanyahu's communications long after its intelligence agencies determined he wasn’t going to strike Iran: they wanted to know if Israel had learned of the secret negotiations.

Netanyahu's efforts to scuttle the deal, eventually ratified this summer, saw him make a speech in March to the US Congress at the invitation of Republican Speaker of the House John Boehner. The move sparked outrage as the invitation was not cleared by the White House, and apparently had been deliberately kept from the Obama administration.

As Israel has launched a massive, and ultimately unsuccessful, lobbying campaign to stymie the deal's passage through Congress, it became clear that monitoring the communications of Israeli officials and leaders of the powerful pro-Israeli AIPAC lobby entailed intercepting those of US lawmakers.

While this contravenes an NSA directive ordering to destroy intercepted communications between foreign intelligence targets and members of Congress, the agency's director can issue a waiver if it is deemed that the communications contain "significant foreign intelligence".

According to WSJ, "NSA removed the names of lawmakers from intelligence reports and weeded out personal information. The agency kept out 'trash talk,' officials said, such as personal attacks on the executive branch."

In a separate subplot of the spying saga, the NSA became aware that Israel has, in turn, repeatedly deployed a sophisticated computer virus to hack through the cybersecurity in hotels hosting the closed-door talks. The report of Israel's snooping was also published in WSJ in May, and categorically denied by Jerusalem.