Israel's "wide-scale" response to Iranian-backed rocket attacks on the Golan Heights have shown the dynamics of deterrence between Tel Aviv and Tehran are being renegotiated.
After the Israeli military (IDF) killed an Islamic Jihad commander in Gaza and targeted another in a strike unconfirmed by Israel in Damascus last week, a series of four rockets were launched Tuesday at the Israeli controlled Golan Heights by an "Iranian force," according to the IDF, all of which were intercepted.
In response, Israel carried out "wide-scale strikes" on what it said were Iranian and Syrian forces on Wednesday, hitting more than 20 targets and killing at least 14 Iranians and Syrians, 3 of them civilians.
Although Israel has long waged a proxy war with Iran in Syria, the Iranian response and Israel's counter-response have aggravated a fragile balance in a regional conflict that threatens to spiral and reflects a splintering in relations between Russia and its Israeli and Iranian allies.
Israel's 'war between the wars'
Israel has long used the tactic of undeclared air raids in Syria in what is known as its "war between wars," a campaign it claims is waged to reduce the capacity of its rivals ahead of any future war.
After pioneering the tactic in a 2007 strike on a suspected Syrian nuclear reactor, it expanded its use on a wide scale, delivering some 800 bombs against 200 targets across the country in 2017-2018, as Iran increased its presence in Syria through its Quds Force, Lebanese ally Hezbollah and other proxies.
Before the most recent conflagration, Israel's last undeclared attack on Iranian backed-militias in eastern Syria on September 9 killed 18 fighters, according to the Syrian Observatory for Human Rights.
But Israel has also attacked Iranian proxies over the border in Iraq, who may have also been responsible for the drone strike on Saudi Arabia's Aramco oil facilities, according to an Iraqi intelligence source who spoke to Middle East Eye.
Ofer Zalzberg, a senior analyst at the international Crisis Group think tank, told DW that Israeli officials had been worried that Iranian proxies could carry out an attack similar to the one in Saudi Arabia on Israeli military, civilian or nuclear infrastructure.
While Iran faces pressure over protests at home and against its influence in Iraq and Lebanon, Zalzberg said the rocket attack on the Golan Heights showed Israeli officials that "Iran is doing something new" and intends to show Israel that its domestic and regional troubles would not stop it from retaliating.
With the threat of another Aramco-style attack and large-scale Israeli strikes on both Iranian and Syrian targets, Zalzberg said both parties are renegotiating the "rules of the game."
What are Iran's capabilities in southern Syria?
Iranian forces and Hezbollah have fought in Syria in support of President Bashar Assad's regime since 2012, but experts are unable to give a definite figure for their numbers and military assets.
While most of Iran's forces — said by Ariane Tabatabai at the RAND corporation to also include Afghan and Pakistani Shia militias — are concentrated in Syria's north, Israeli media reports cite an increasing concern with transfers of precision-guided missiles to Hezbollah and their reported presence in the Golan Heights.
On November 5, Israeli military official Aharon Haliva said "there are Iranian Quds forces in the Golan Heights and that's not fear-mongering, they're there," according to Israeli media, an assertion that Zalzberg said was "highly plausible."
Crisis Group's Heiko Wimmen said that the rumors of Iranian recruitment in Syria's southwest were highly credible but the broader distinction between Syrian groups and Iranian groups is blurry and information about exactly where the recent rockets were fired from is lacking.
Russian troops are also stationed on the border, holding Russia's allies in Damascus and Tel Aviv at arms-length from one another, but Wimmen said their limited presence meant they were unlikely to be able to monitor potential Iranian allies.
"What are the Russians going to do if you have people who are nominally part of the Syrian army but then they are being paid by Hezbollah and Iran?" Wimmen said. "How can they really monitor this?"
Russian mediation breaking down?
While Russia has managed to maintain close ties with Iran and Israel throughout the Syrian war, it fears the latest escalation could unravel the fragile stability it has achieved on behalf of Assad.
"The strikes on the territory of this Syrian sovereign state completely violate international law," Deputy Foreign Minister Mikhail Bogdanov said on Wednesday, adding Israel's attacks "will lead to an escalation of tensions."
Kirill Semenov, a Syria expert from the Russian International Affairs Council, told DW that Iran's expansion into the southern de-escalation zone had created tensions between Moscow and Tehran but that Russia had no problems with strikes on Syria as long as they didn't threaten Russian lives.
Ofer Zalzberg said Bogdanov's "strongly worded" statement indicated Russian-Israeli ties were under strain because they denied any legitimacy to the Israeli response.
But Heiko Wimmen said that Moscow may have been using an agreement struck after a 2018 incident that claimed 15 Russian soldiers that required Israel to warn Russia before a strike to tip off the Iranians, an arrangement Israel may not be entirely unhappy about.
"If there is a pattern, then the moment an Israeli attack leads to casualties, particularly Iranian casualties, then the likelihood of an Iranian reaction, like shooting missiles at the Golan, climbs," Wimmen said. "There were unconfirmed reports that the Iranians who died in this attack were advisors to Assad, so we can imagine the likelihood of another missile attack on the Golan in the next few days or two weeks will increase."