Israeli Prime Minister Benjamin Netanyahu met with Russian President Vladimir Putin on Wednesday.

Netanyahu left saying he thought Russia wouldn't intervene in Israel protecting itself.

On Wednesday night, a massive air war broke out between Iranian forces in Syria and Israeli jets; Israel has said it destroyed numerous Iranian sites.

Putin has warned Netanyahu against attacking Syrian sites, but when it comes to Israel versus Iranians, he seems not to care.

Israeli Prime Minister Benjamin Netanyahu met with Russian President Vladimir Putin at Moscow's Victory Day parade on Wednesday. Hours later, a massive air war broke out in which, Israel says, it destroyed dozens of Iranian sites in Syria.

Statements from Netanyahu suggest that Putin may have given the green light before the attack.

Netanyahu left Russia saying that "there is a need to ensure the continuation of military coordination between the Russian military and the Israel Defence Forces." On Wednesday night, the IDF coordinated a massive series of strikes on Iranian targets across Syria, Russia's ally, Israel said.

Israel says it has hit targets in Syria more than 100 times since 2012 and maintains that it will continue to strike wherever it sees Iranian forces and assets that pose a threat to its security.

Russia has typically not acknowledged the Israeli incursions, but the fighting escalated massively on Wednesday night.

The IDF told Israel's Channel 10 News that more than 50 targets were hit in the strike, making it the largest attack carried out by Israel in Syria since the two signed an agreement following the end of the 1973 Arab-Israeli War.

Israel said that around 1 a.m. local time, 20 Iranian Grad and Fajr rockets came streaking in toward northern Israel. The rockets, Israel said, were either intercepted by the Iron Dome defense system or fell short of their targets.

The Iranian barrage was expected. Israel had opened bomb shelters and warned its citizens of an impending attack after several suspected Israeli airstrikes had killed Iranians in Syria and laid waste to hundreds of rockets.

After the salvo, 28 Israeli jets flew over Syria, firing nearly 60 rockets and 10 surface-to-surface missiles, said Michael Horowitz, an analyst at the security consultancy LeBeck International, citing Russia's defense ministry.

Putin's role in this

Russian President Vladimir Putin, left, and Israeli Prime Minister Benjamin Netanyahu. Pool/Maxim Shipenkov via Associated Press

Putin stepped into the Syrian civil war in 2015 as a guarantor of Syrian President Bashar Assad's security. He has stood by Assad even as the Syrian leader has been accused of conducting chemical warfare and other barbaric acts on his own people.

Each of the two times the US struck Syria, in what Washington characterized as punishment for chemical warfare, the prospect loomed that Russia could defend the Syrian targets or retaliate on their behalf.

But that does not appear to be the case when Israel strikes Syria.

In February, after Israel downed an Iranian drone it said was armed and flying in Israeli airspace, IDF jets were said to have knocked out half of Syria's air defenses in a massive air war; Israel lost an F-16 to Syrian missiles.

"The response to the downing of the Israeli jet was intended to be a lot more violent," the investigative journalist Ronen Bergman wrote in an op-ed article in The New York Times at the time.

A "furious phone call" from Putin was enough to make Netanyahu "cancel the plans," Bergman wrote. Netanyahu, most likely out for blood after losing a jet to Syrian forces, then offered a more muted response.

In mid-April, after Israel was again thought to have attacked Iranian forces in Syria, Putin called Netanyahu to warn him against striking targets in Syria.

Earlier this month, an Israeli security cabinet minister suggested that Israel could kill Assad if he were to interfere in Israel's campaign to stop Iran's buildup of forces on its border.

Russia said Syrian air defenses shot down several Israeli missiles on Wednesday night.

Russia has staked its credibility in the Middle East on ensuring Assad's survival against Western forces, which have openly mulled deposing the Syrian leader.

But when it comes to Israel striking Iranians in Syria, Ephraim Sneh, a former Israeli deputy defense minister told Business Insider he didn't think the Russians "actually care too much."

Russia operates advanced air defenses and an air force in Syria that have the ability to engage Israeli targets, but by all accounts, Moscow's forces stood down when Israeli missiles started flying.