On Sunday, a missile attack from Syria left a 13-year-old boy dead in the Golan Heights, in what analysts and Israeli defense officials called the most significant escalation on that border since the start of the Syrian conflict more than three years ago.

Early Monday morning, in retaliation, an Israeli Defense Forces spokesman said Israel had fired guided missiles from the ground and rockets from the air at nine positions across the Syrian border, including a military command headquarters.

The fight between longtime nemeses Israel and Syria has simmered at a slow but increasing boil.

Since the start of Syria’s war there have been periodic exchanges of fire across the Syrian-Israeli frontier. Last year Syrian rebel groups briefly took control of the Golan border post. Israel has also attacked convoys in Syria that it said were ferrying weapons to Hezbollah. Typically, Israeli defense forces also fire rockets at Syrian army targets in retaliation for cross-border fire that originates in Syria.

We asked Tommy Steiner, senior research fellow at the Institute for Policy and Strategy and IDC Herzliya, and Jonathan Spyer, senior research fellow at the Global Research in International Affairs Center in Herzliya, to weigh in on the significance of this week’s events.

Syria Deeply: What made this weekend’s attack different?

Tommy Steiner: This is not the first time that Syrian regime military units have fired towards Israeli targets, although it’s rather rare. The reason Israel assumes it was the army is because it’s a type of missile only held by the Syrian army. It wasn’t a rocket; this is not a case where a rocket fell by mistake. It was a targeted strike at civilians working on a security fence. The casualty was a 13-year-old boy, an Arab-Israeli who was with his father on his first day of school holidays.

It appears that this was a deliberate attack, not a mortar shell falling out of nowhere. Therefore, the Israeli retaliation on Syrian army posts near the border was more significant than previous incidents. At this point I think the Israeli military and defense establishment are highly aware of the fluidity of the situation east of our border with Syria. Several months ago I said it was only a matter of time that what’s happening in Syria will spill over into Iraq. Then this morning, there are reports that ISIS took border crossings with Jordan from the Iraqi military. The latter could be watershed, placing Israel in a strategically sensitive position, and Jordan even more so. Jordan now has to contend with the implications and spillover of two regimes that are crumbling and falling apart.

Jonathan Speyer: We’ve been noticing for a while that having been quiet for 40 years, the Golan has now become an active border. It’s not the first time that Hezbollah or pro-regime elements have targeted Israeli targets on the border, but it is the first time it’s resulted in [an Israeli] fatality. For Israel, a young boy was killed and this turns it into an event of a different magnitude requiring a different response [than past retaliations]. And that is what we have witnessed.

Syria Deeply: Why would the Syrian regime attack Israel? What does it stand to gain?

Steiner: I don’t think it was a decision made by Assad himself: “OK, let’s take an Israeli target.” It was probably a commander in the field who directed the strike. I don’t think it came down from the top of the regime. But the Israeli retaliation was sending a message to make sure future incidents like that will not be repeated. The Syrian army should be very cautious not to harm Israeli citizens or military personnel.

Syria Deeply: What message is Israel sending? What is the scope of the retaliation?

Speyer: Initially, Israel thought this was coming from the rebels because of the area the missile appeared to be launched from. Given that Jabhat al-Nusra is also active in the Quneitra area, the attacks could be carried out by Nusra. We know that Hezbollah has a presence close to the border, and I’m speculating that it’s just as likely that Hezbollah would have carried this out. But Israel says that the regime is the body responsible for keeping peace in this area, and so that’s who’s going to pay the price.

Israel doesn’t want to see this deteriorate into a conflict, but it wants to send a message that if [attacks like] this are going to carry on, there will be a heavy price to pay for them. From Israel’s point of view, the message has been delivered and the ball is now in Assad’s court. Israel’s assumption is that Assad is sufficiently busy with other fronts, and that he will stay busy and will not wish to escalate a further [fight] with Israeli defense forces.

Israel obviously has identified Division 90 of the Syrian army as the group who should – and have now – paid the price for what took place. We don’t know if that’s who was directly responsible for launching the attack. It could have been Hezbollah. Israel likes to have an “address” – as far as they’re concerned, if anything goes wrong in the area under your control, you pay the price.

Syria Deeply: What happens next between Israel and Syria?

Steiner: At this point, Israel is still providing medical and other forms of relief to Syrian refugees in [the Golan]. I assume that will continue, and I think the Israeli forces will be very alert now to possible changes on the ground. There is concern here that the jihadist elements along the border might also turn against Israel. It’s a working assumption [in the Israeli government] that this could be a future development.

Speyer: If it was Hezbollah, this event could lead us to a fascinating situation. In the past, Hezbollah used to use southern Lebanon as the [jumping-off point to hit Israel], and now we see a reverse in which Hezbollah, if they were the ones who launched the missile, prefer to keep the southern Lebanon border quiet while attacking Israel from the Golan.