This is the third time I've tried to write this, so apologies for the delay.
As you may have gleaned from mainstream media, israel has recently re-escalated the airstrikes on Syria after they'd been forced to stop following the incident leading to the Russian IL-20 being shot down.
On the day of January 21st, two israeli F-16s attempted to strike a target at Damascus International Airport - they fired seven missiles (likely Delilah-type cruise missiles, though no official word yet), all of which were intercepted and shot down by Syrian air defence. Presumably humiliated, the IAF took to Twitter to scold Syria for ‘aggressively shooting down their missiles’ (yes, seriously), and launched a much larger scale attack several hours later.
The second attack was again launched from F-16s, as before from the airspace of southern Lebanon. This time, however, an estimated 40 missiles were launched with 25-30 intercepted (no official account has been released at this time). Along with the significantly higher number, other munitions were used as well - at least one IAI-HARROP anti-radar drone was used toward the end of the attack, and it was able to destroy a PANTSIR-S1 complex after the PANTSIR had expended all munitions and was awaiting reloading. Officially, one PANTSIR was destroyed and material damage was done to several warehouses on the grounds of Damascus International Airport. Four SAA soldiers were reported killed and six injured, presumably the PANTSIR’s crew.
The reason for the uptick in attacks, including the now-infamous Christmas Day raid is likely the result of the transfer of potent S-300-PMU2 systems from Russia. Syria has long-desired to purchase the long-range SAM complex, but for years the purchase was placed on hold due to israeli influence, specifically their fear that the advanced long-range radar of the system could put a stop to israeli air superiority, and by extension their ability to attack with impunity within the region. Following the aforementioned incident where israeli attacks led to the destruction of a Russian recon plane (and the death of all servicemen on board), Russia immediately began the transfer of S-300 units to Syria as well as deploying many of their latest ECM complexes down the Syrian coast, which is why the recent israeli attacks have all come from the south of Lebanon.
The S-300s are not yet fully operational though. It would seem that their radar is partially integrated into Syria’s anti-air network given that their intercept rate has risen to roughly 80% since the transfer, but the systems are presently being (passively) operated by Russian veterans while the SAA is trained on their use. The official timetable is for the SAA to be able to operate them independently by ‘late January’, but the Russian MoD made the statement today that Syrian crews are not yet fully trained.
Knowing this, it appears that israel sees its ‘window of opportunity’ to attack with impunity rapidly closing, so what is their goal in ramping up the attacks?
Israel's party line is that they're attacking Iranian and Hezbullah forces, claiming it to be some sort of pre-emptive ‘self-defence’, but the claim is dubious (and justification absurd). For one, there is no significant Iranian military force in Syria, IRGC or otherwise - they're assisting the SAA in the context of training, intelligence and advisement, and the only forces they have are small groups to guard their advisors. Hezbullah has done much of the heavy lifting in the war; Iran has only provided support.
For another, israel has been regularly targeting Damascus Airport, which is in the South of the country where, for the most part, Hezbullah does not operate. This was actually negotiated to appease israel - when the SAA moved to retake Daraa and Quineitra, israel was terrified that Hezbullah would move to retake their occupied Golan (judging by chatter between Hez and the SAA, it's likely they were right) so an agreement was made through Russia that Hezbullah would not participate and israel would not attempt to hinder the offensive. As a result, most Hezbullah activity is in the north and northeast of the country.
The real reason for these attacks, I believe, is to goad Syria into responding, and in turn to draw her (and her allies) into a wider war. Israel's goal has always been to destabilize Syria and destroy it as a functional state in order to weaken Iran - it played no small part in initiating the war in Syria, and has long supported rebels of all stripes (including Al-Nusra, ISIS and most of the US and Turkish-backed factions) with money, munitions and medical treatment (it may have been Turkey that bought oil directly from ISIS, but for the most part israel was always the end-buyer). One by one, all of their plans have failed, and they absolutely do not want to see the Syrian state rebuilt.
It's important to note that israel, Iran and most regional powers see a future war as inevitable given that the sides have goals that directly contradict one another - israel has no chance of winning a direct conventional war alone (I even question whether they could ‘win’ with their undeclared nuclear stockpile), doubly so if Iran is supported by China and/or Russia, so she’s going out of her way to create a conflict that draws in her traditional US and European ‘allies’ before Syria, Iran and Hezbullah (and Iraq to a lesser extent) are able to regain and consolidate their strength.
In short, we can expect a lot more jedi trickery in the near future. Once the S-300s come online it’s likely the SAA will begin taking aim at the F16s rather than just the missiles they're firing as the S-300s are IFF-capable (a large part of the reason why the SAA hasn't tried to down them recently is because the jets have been ‘hiding’ behind aircraft with much larger radar cross-sections - this is how the IL-20 was shot down, and they repeated the stunt by ‘hiding’ behind commercial craft on Christmas day), so we can expect some very loud kvetching and rapid escalation should that play out.