Israel’s hawkish defense minister Avigdor Lieberman has blasted the Syrian regime, warning that Israel will destroy their air defense system if they dare to attack Israeli fighter jets again.

Lieberman’s comments on Sunday came after Syrian anti-aircraft missiles were fired at Israeli warplanes which had just attacked several targets near Palmyra Thursday evening. Israel claimed that their air force was targeting a convoy of Hezbollah vehicles.

Since the beginning of the bloody civil war in Syria in 2011, a number of airstrikes in the country – many close to the Lebanese border – have been attributed to Israel. Israeli authorities have rarely commented on these strikes, with Syria largely staying silent too.

But despite this reticence to discuss any missions in Syria, Israeli government officials have been keen to repeatedly declare that they will not tolerate the militant Lebanese group Hezbollah gaining access to ‘game changing weapons,’ warning that they will do whatever it takes to stop that from happening. Part of this strategy includes preventing the possible transfer of arms from Syrian fighters.

In response to Thursday’s incident, the Israeli Defense Force (IDF) released a rare statement taking responsibility for the attack in Syria, but denied that any Israeli planes had been shot down as the Assad regime had claimed. They also confirmed that their ‘Arrow’ defense system had successfully intercepted one of the missiles headed to a populated location in the Jordan Valley.

Israeli Prime Minister Netanyahu also spoke out about the strike Friday, defiant in his justification: “When we identify attempts to transfer advanced weapons to Hezbollah and we have intelligence and it is operationally feasible, we act to prevent it,” he said.

Yaakov Lappin, a defense affairs correspondent and analyst, told VICE News that Assad’s decision to fire ballistic missiles at Israel represented the largest escalation between Israel and Syria since the civil war broke out in 2011, explaining that the incident represented an important rise in aggression between the two countries.

“This represents the most significant use of fire-power by Syria against the Israeli air force (IAF) in recent years as far as we know. That said, had one of the missiles not been headed to Israeli territory we might have never heard about this incident.”

Things continued to escalate on Sunday morning when Syrian media reported that Israel had assassinated a pro-Assad soldier with a drone as his truck was driving in the Quneitra region of the Golan Heights – an area controlled by Syria.

Israel declined to comment on these reports, but Israeli media has speculated that the man was involved in planning attacks on Israel’s Syrian border, and that the strike was a response to Syria launching surface-to-air missiles at Israel.

Lappin stressed that Assad would only have decided to use missiles against Israel after getting the go ahead from his closest allies.

“I think the Assad regime is not in a position to make its own decisions on matters that can lead to war with Israel. I believe they are part of an axis – they are a junior member of that axis – the senior members being Russia and Iran. Without their support, the Assad regime would not be in existence today. It seems to be clear to me that they had to consult quickly with the Iranians, and possibly the Russians, before deciding to fire these missiles.”

Mindful of this, Netanyahu told reporters Tuesday that he had made it clear to Russian President Putin that Israeli air force missions would continue over Syria. “If there is a feasibility from an intelligence and military standpoint – we attack and so it will continue,” he said.

Despite this defiant attitude from Netanyahu, Lappin warns that the Syrians feel emboldened by Russian support. “The Assad regime has gained a lot of victories recently on the battlefield in Aleppo. The Russians are entrenched and are showing no signs of going anywhere and the Iranians are very committed to Assad’s survival.”

“Assad may have felt that he was now in a position to send Israel a signal that Israel shouldn’t get used to a lack of a response. That now he wants to change the rules of the game and these strikes would not go unanswered anymore.”

Although Israel and Syria technically remain at war, things had been relatively quiet on the Israel-Syria border until the civil war broke out in 2011.

Since then, there has been heavy fighting across the border, and mortar shells and rockets have landed in Israel – mostly accidental spillover from the war. The IDF policy has been to fire at Syrian army posts or at the original source of the rocket fire.

This latest retaliation shows that Israel may well have misjudged Assad’s ability to hold onto power. And with the Syrian regime fast clawing back control of rebel-held areas, their stance on Israeli attacks could become harder still.