President Barack Obama’s last-minute decision not to carry out an intended punitive strike against Syria’s President Bashar Assad this summer, after Assad killed almost 1,500 of his own people with chemical weapons, was influenced by secret US back-channel discussions with Iran, Israel’s security and intelligence community reportedly believes.

The issue of Assad’s chemical weapons use came up in the secret US-Iran contacts held in recent months in Oman, Israel’s Channel 2 news reported Friday, and it quoted unnamed Israeli intelligence and security sources asserting Obama’s change of heart was affected by those contacts.

The report speculated that Iran persuaded Assad to agree to dismantle his chemical weapons capability in return for Obama not carrying out the intended attack.

The report underlines Israeli concerns, frequently stated by Prime Minister Benjamin Netanyahu, that Iran is fooling the US about its ostensibly moderate intentions, and that the US is being duped into unjustifiably warming relations with Iran, while Israel is gradually becoming isolated in its unbending opposition to Iran’s nuclear program. The same TV news broadcast also quoted unnamed Israeli government officials denouncing Obama for mishandling the Geneva nuclear negotiations, with the result that Iran has been granted the “right” to enrich uranium and economic sanctions pressure on Iran is collapsing.

The Obama administration last week acknowledged holding months of secret back-channel talks with Iran ahead of the interim deal on Iran’s rogue nuclear program that was signed last week by the P5+1 powers and Iran in Geneva. The president reportedly informed Netanyahu of those contacts when he visited the White House in late September soon after they became “substantive.” Israeli reports have claimed that the back-channel was opened much earlier than acknowledged by the Obama administration, and Israeli officials have privately protested that the US did not inform Israel fully of those contacts.

Friday’s Channel 2 report recalled that the Obama administration was so certain that its forces were about to attack Syria in the chemical weapons crisis at the end of August that US officials telephoned Israel’s prime minister and defense minister to give them “advance warning” the attack was about to take place. The phone calls were made shortly after Secretary of State John Kerry on August 31 had accused Assad’s regime of an August 21 chemical weapons attack that killed 1,429 Syrians. Israel’s leaders were told explicitly that the US would be taking punitive military action against the Assad regime within 24-48 hours.

Friday’s report said that Kerry personally telephoned Israel’s leaders to inform them of the imminent attack, and that Britain’s Foreign Secretary William Hague also made such a call. The calls were made so that Israel could take steps to defend itself against any potential Syrian retaliation that might target the Jewish state.

In fact, however, Obama on September 1 surprisingly announced that he would seek Congressional authorization before a strike on Syria. Ultimately Obama did not carry out the narrow, punitive action he had said he was planning, instead joining a Russian-led initiative for a diplomatic solution aimed at stripping Assad of his chemical weapons.

The Times of Israel reported claims Friday that the secret back channel of negotiations between Iran and the United States began several years ago, and that it has also led to a series of prisoner releases by both sides, which have played a central role in bridging the distance between the two nations.

In the most dramatic of those releases, the US in April released a top Iranian scientist, Mojtaba Atarodi, who had been arrested in 2011 for attempting to acquire equipment that could be used for Iran’s military-nuclear programs.