Beirut - Lebanon woke up tense on Monday following an Israeli air strike that targeted and killed six Hezbollah members in Syria's south.
Now the question on everyone's lips is when and how Hezbollah will respond. Analysts say the targeted assassination of several high-level Hezbollah fighters in Quneitra is considered a huge loss for the party and a game changer in the ongoing war between Hezbollah and Israel.
"These assassinations have changed the rules of the game," Amal Saad, a professor at the Lebanese University and an expert on Hezbollah, told Al Jazeera. "Hezbollah will respond, and very swiftly this time. It is in a position today where it can respond without leading to a full-blown war.
"The latest attack is significant," Saad added. "This was not a random strike on a convoy; this was a targeted assassination, which probably took a lot of planning. It was a very valuable target, so the party has to respond."
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Hezbollah, which has been fighting inside Syria alongside the Syrian army, has been struck several times by Israel in both Syria and Lebanon, but this is the first time such a strike has killed so many high-level targets, resulting in a big loss for the party.
On Sunday afternoon, a Hezbollah unit was conducting a field inspection in the area of the Amal Farms in Quneitra, southern Syria, when an Israeli helicopter struck two cars - a Cherokee and a Kia - with two missiles. They were reported to be a mere 400m away from a United Nations position, and 7km from the Israeli-occupied Golan Heights.
These assassinations have changed the rules of the game. Hezbollah will respond, and very swiftly this time. It is in a position today where it can respond without leading to a full blown war.
Israel launched a similar attack in June 2013, killing a member of the Syrian resistance in the area. It has also conducted several air strikes, including in Damascus, against reported weapons convoys destined for Hezbollah.
A Hezbollah member was also killed in southern Lebanon in September 2014 after Israel remotely detonated a spying device he was dismantling. Hezbollah responded two days later, targeting an Israeli tank with an IED in the Israeli-occupied Shebaa Farms. Hezbollah Secretary-General Hassan Nasrallah has warned repeatedly that strikes in Syria were a red line.
According to Walid Charara, a political analyst based in Beirut, the recent targeted attack by Israel on Hezbollah in Syria has now expanded the battle lines between Hezbollah and Israel.
"This action demonstrates that Israel is looking to expand the confrontation between itself and Hezbollah," he told Al Jazeera. "They used to hit the party in Lebanon; now it's doing so in Syria. You can say the front is now open from Naqoura to the Golan Heights and beyond.
"This is a direct attack on Hezbollah members in Syria, so Hezbollah will respond, but when and how, it will be a surprise."
According to Charara, Israel is attempting to test Hezbollah's capabilities and change the dynamics on the ground. "Hezbollah will not allow this aggression to pass, as it leaves the door open for further aggression if it doesn't respond."
Only days ago, Nasrallah warned Israel in a three-hour televised interview against making any "stupid" moves in Lebanon and Syria. He said the party has the capability to strike any place in Israel, and its fighters are ready to occupy Galilee and beyond.
He also warned Israel against thinking the party's capabilities had weakened as a result of its participation in neighbouring Syria, saying they are ready and prepared. "As a resistance, we are stronger than ever."
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Following Sunday's attack, sources within the party told Al Jazeera there would be "calculated operations at any time and any place" in retaliation.
The killed fighters include a top-level commander, 43-year-old Mohammad Issa (known as Abu Issa), reported to be the head of Hezbollah's special forces in the Golan, and Jihad Mughniyeh, 27, the son of slain Hezbollah commander Imad Mughniyeh, who was also assassinated in Syria in February 2008. Jihad was reported to have been personally mentored by Iran's Quds Forces leader Qassem Soleimani, and was considered by many close to the movement as a rising star, moving quickly up the ranks.
"The assassination of Jihad is a loss for Hezbollah. The same goes for the others who were very important too," Saad said, adding that Hezbollah now has several options available to it in terms of executing a response. "It could either use the Shebaa Farms [in south Lebanon] or now the Golan Heights.
"Hezbollah has to prove it is not weak, and historically it has shown it does carry out its threats," she said. "The assassinations by Israel have now destroyed the status quo between the two, and therefore Hezbollah has to respond to re-establish that."
Source: Al Jazeera