With Israel poised to attack Iran, having already blindsided friends and foes alike with its blitz against Lebanon's Hezbollah movement, all the talk is of an inexorable slide towards a new, pan-Middle Eastern war.
Yet brakes remain to halt a regional fall into a wider conflagration that would lock Israel and Tehran into escalating conflict and suck in other nations, according to several people with experience in intelligence and military decision-making.
Israel is unlikely to flinch from launching an aerial barrage on Iran as soon as in the coming days in retaliation for Tehran's decision to launch about 180 ballistic missiles at Israel on Tuesday, the experts told Reuters .
"Whoever attacks us – we attack them," Israeli Prime Minister Benjamin Netanyahu told his security cabinet on Tuesday night, summing up his doctrine of deterrence.
Israeli officials have nonetheless told US counterparts their response to Iran's attack will be "calibrated", though have yet to provide a final list of potential targets, according to a person in Washington familiar with the discussions who requested anonymity to discuss security matters.
"I think that the targets that will be selected, will be meticulously, very carefully selected," said Avi Melamed, a former Israeli intelligence official and a negotiator during the Palestinian intifadas, or uprisings, of the 1980s and 2000s. Sites of Iranian military importance such as missile infrastructure, communication centres and power plants are likely candidates, he added.
Israel is less likely to hit the oil facilities that underpin Iran's economy or its nuclear sites, according to many of the experts interviewed, who include more than half a dozen former military, intelligence and diplomatic officials from the United States and Middle East.
These highly sensitive targets would be expected to draw an escalated Iranian response including the potential targeting of the oil production sites of U.S. allies in the region including Gulf Arab states, they said.
US President Joe Biden said on Thursday he would not negotiate in public when asked if he had urged Israel not to attack Iran's oil facilities, hours after he contributed to a surge in global oil prices when he said Washington was discussing such Israeli strikes.
Israel has surprised much of the world with the scale of its offensive against the Iranian-backed group Hezbollah, from the detonation of thousands of militants' pagers and walkie-talkies, to the assassination of leader Sayyed Hassan Nasrallah in a Beirut airstrike and a ground incursion into southern Lebanon.
"It would be unwise for outsiders to try to predict Israel's attack plan," said Norman Roule, a former senior CIA officer who served as the US intelligence community's top manager for Iran from 2008 to 2017.
"But if Israel decides on a proportional yet substantial strike, it may elect to limit its attacks to Iranian missile and IRGC-Quds Force architecture that supported attacks by Tehran and its proxies on Israel."
Roule, senior adviser to the United Against Nuclear Iran advocacy group, said Israel could strike Iranian installations that refine gasoline and diesel for domestic consumption while sparing those that load oil exports, depriving Tehran of a justification to retaliate against the facilities of Gulf states and limiting a spike in crude prices.
IRAN: A CAUTIOUS ADVERSARY
Any wider Middle Eastern conflict is unlikely to resemble the grinding ground wars of past decades between opposing armies.
Only two sovereign states, Israel and Iran, have so far militarily locked horns over the past year, and they are separated by two other countries and vast tracts of desert. The distance has limited their exchanges to strikes by air, covert operations or the use of proxy militias such as Hezbollah.
Iran has long vowed to destroy the state of Israel, yet has proven to be a cautious adversary in this crisis, carefully calibrating its two aerial attacks on Israel, the first in April - after Israel bombed the Iranian consulate in Syria, killing several commanders - and the second this week after Nasrallah's killing.
The only reported death from Iran's two attacks was a luckless Palestinian hit by a missile casing that fell from the sky into the West Bank on Tuesday.
Egypt, which fought wars with Israel in 1948, 1956, 1967 and 1973, and signed a peace treaty in 1979, is widely thought to have little interest in getting pulled into the conflict. Syria, an Iranian ally which has also battled Israel in the past, is sunk in economic collapse after a decade of civil war.
The wealthy Gulf states, close US security partners, want to steer clear too. Two sources with knowledge of the matter told Reuters that Gulf ministers held talks with Iran on the sidelines of a conference in Qatar on Thursday, seeking to reassure Tehran of their neutrality in any escalation that could engulf their oil production sites.
The United States says it will defend Israel to the hilt against their common foe, Iran and its proxies, but no one thinks it will put boots on the ground like it did in the two Gulf wars in 1990 and 2003 when it went to war against Iraq.
The Oct. 7 attack on Israel by fighters from Palestinian group Hamas killed 1,200 people, while the ensuing Israeli battering of Gaza has killed nearly 42,000 people and displaced almost all the enclave's 2.3 million population, according to local officials and U.N. figures. Clashes between Israel and Hezbollah have also forced thousands of families in northern Israel and southern Lebanon from their homes.
The United States is not pressing Israel to refrain from military retaliation against Iran's latest attack - as it did in April - but encouraging a careful consideration of potential consequences to any response, according to the person in Washington familiar with the discussions.
Washington has proved to have limited influence over Israel though, and Netanyahu has remained implacable about the targeting of his country's enemies since the Hamas attack.
"The Israelis have already blown through any number of red lines that we laid down for them," said Richard Hooker, a retired US Army officer who served in the National Security Council under Republican and Democratic presidents.
The US presidential election on November 5 also means Biden's powers of persuasion are limited during his final months in the White House.
Biden told reporters on Wednesday that Israel has a right to respond "proportionally". He has made it clear he does not support an Israeli strike on Iran's nuclear facilities, where Israel and Western states say Iranians have a programme aimed at building nuclear weapons, a charge Tehran denies.
Hooker said targeting such sites was possible but not probable "because when you do something like that you put the Iranian leadership in a position to do something pretty dramatic in response".
Israel, which is widely believed to be the Middle East's only nuclear-armed state though neither confirms nor denies that it possesses such weapons, has long considered Tehran's nuclear programme an existential threat. Iran's nuclear sites are spread over many locations, some of them deep underground.
OIL FACILITIES: 'HIT THEM HARD'
In Washington, whose sanctions on Tehran have failed to shut down Iran's oil industry, there are calls for strikes on refineries and other energy facilities.
"These oil refineries need to be hit and hit hard because that is the source of cash for the regime," U.S. Republican Senator Lindsey Graham said in a statement.
For Arab states on the other side of the Gulf, action targeting Iranian oil facilities would set off alarm bells, fearing a vengeful Tehran.
Saudi Arabia, which until the Gaza war was in talks on a U.S. defence pact and a possible normalisation deal with Israel, saw its oil sites come under attack in 2019 from the Iran-backed Houthis in Yemen, where the kingdom was embroiled in conflict for years.
Oil prices have traded in a narrow range of $70-$90 per barrel in recent years despite the war between Russia and Ukraine and conflict in the Middle East.
Analysts say OPEC has enough spare capacity to cope even if all Iran's production was knocked out. But it would struggle to compensate if an escalation damaged oil capacity in the producer group's linchpin Saudi Arabia or the United Arab Emirates.
