Iran and Israel are sworn enemies who, after decades of a covert shadow war, have finally taken their conflict into the open. But when it comes to a post-Assad Syria, they share a common goal: both want to keep the country’s new government as weak as possible.

From an Iranian perspective, hostility to Damascus seems logical. Bashar Al Assad’s establishment was a key pillar of the “Axis of Resistance”. The former president also allowed Iran to use Syrian territory as a vital land bridge to supply another of its regional allies: Lebanon’s Hezbollah.

By contrast, Syria’s new President, Ahmad Al Shara, has promised that the country will now be a responsible regional actor. Government forces have intercepted several weapons shipments bound for Lebanon. Throughout Syria’s long civil war, Mr Al Shara and his Hayat Tahrir Al Sham militant group fought many bloody battles against Hezbollah and other Iran-backed factions.

The chances of Mr Al Shara letting Iran use Syria for business as usual, then, are negligible.

In response, Iran is trying to turn Mr Al Assad’s departure from a defeat into a mere setback. In a leaked recording that surfaced earlier this year, a senior Islamic Revolutionary Guard Corps official suggested that Tehran should reactivate its “networks” in Syria.

Israel may think Iran is weaker than ever – this was, after all, a key motivation for launching strikes last week. Yet Iran is down but not out in Syria. Mr Al Assad may have fled, but Iran’s networks remain intact and willing to advance Tehran’s interests. To be able to do so, they need to keep the new establishment and its security forces too weak or too distracted to act against them.

It is therefore perplexing that Israel shares this vision. This is especially true given that Mr Al Shara has publicly pledged – on several occasions – that the new Syria will no longer confront Israel.

For their part, Israeli officials have labelled Mr Al Shara “pure evil” and a “jihadist terrorist”. Israel has launched more than 800 air strikes within Syria and its troops have occupied over 460 square kilometres of Syrian territory since the former regime collapsed.

These attacks are preoccupying Syria’s security forces and further destabilising the country – exactly the chaos that Iran needs to re-establish itself there.

Tehran has exploited Israel’s short-sighted policies to do just that. The Islamic Resistance Front in Syria is an armed group that seeks to “resist” Israel’s occupation. To legitimise itself and recruit followers, the group has filmed its attacks on Israeli positions. The IRFS’s claim to be non-sectarian and without foreign backers is a hollow one. The group’s logo – a near clone of Hezbollah’s – betrays its true goals and loyalties.

Equally tellingly, this strategy is a carbon copy of how Iran entrenched itself in Lebanon in the mid-1980s. In 1985, Israel sought to end a disastrous intervention in that country, but it also felt that continuing instability meant it could not safely leave.

Israel therefore occupied an 800-square kilometre “security zone” in southern Lebanon. This played straight into Iran’s hands, allowing Tehran to cultivate ties to southern Lebanon’s Shiite community. The result was that the “security zone” did not make Israel safer. It created, sustained and legitimised a new threat: Hezbollah.

Old habits apparently die hard, given that Israel is making the same mistakes in Syria today.

Now, as then, it faced an inevitable blowback: on the evening of June 3, the IRFS fired two rockets from within Syria into the Israeli-occupied Golan Heights. Israel launched retaliatory strikes and has promised more to come. Israel’s Defence Minister, Israel Katz, threatened Mr Al Shara’s government by holding them “directly responsible” for the attacks.

Yet Israel cannot have its cake and eat it. In February, Israel demanded that Mr Al Shara’s government demilitarise all Syrian territory south-west of Damascus. This created a power vacuum that Iran quickly filled. It was not Mr Al Shara who is at fault. This was Israel’s doing.

The timing of the IRFS’s attack was no coincidence. US President Donald Trump’s recent visit to the Gulf caused Israel to drastically change its Syria policy. Under US pressure, it engaged in furtive talks with Mr Al Shara’s government. Israel’s leaders dropped their bellicose rhetoric. Israeli media even published leaks of what an Israel-Syria “normalisation” agreement might look like.

Israel’s uncompromising response to the rocket attacks put this welcome change in jeopardy. Iran was happy to let Israel use its military edge to effectively advance Tehran’s interests in Syria. This is why it saw Israel’s recent course correction as an unwelcome development. Iran is now using a tried-and-tested method to nudge Israel back towards its original bellicose stance.

Even as it strikes Iran directly, Israel appears to also be reverting to form in Syria by further embedding itself in its territory. Since Israel’s air force struck Iran, its troops have launched at least three raids inside Syrian villages.

This suits Iran. While under pressure on the home front, Iranian-linked Iraqi militias have attacked Syrian government forces. Their probable goal is to infiltrate Syria and use that country to open another front to attack Israel. It is therefore now more important than ever that the new powers in Damascus are strong, stable and functioning. This is the only way they can thwart Iran’s efforts, while Israel is busy elsewhere.

Before Mr Trump’s Gulf tour, Israel lobbied hard for the US to retain its long-standing sanctions against Syria. The UAE, Qatar and Saudi Arabia, by contrast, urged the American President to do the opposite. Iran did not have a voice, but its leaders might conceivably have backed Israel’s position.

The Gulf states won that round. Their engagement with Washington re-shaped not only the US’s approach towards Syria, but Israel’s policies as well. Iran’s subsequent provocations and Israel’s response now require another Arab intervention. It is in no one else’s interests that Tehran re-assert itself in Syria.

That Israel shares the same goals as Iran in Syria and is doing exactly what Tehran wants there – even while both states are at war – should give it pause for thought.