Bekkaa Air War et al.
For an excellent account of Syrian failings in the Bekaa Valley Air Battle read https://www.airpower.maxwell.af.mil/airchronicles/apj/apj89/win89/hurley.html.
It looks like the Israelis tried the same trick again according to ALASTAIR CROOKE of Conflict Forums.
"The Syrians saw on their radars the four fighters that penetrated into Northern Syria from the Mediterranean; but they also saw the much larger numbers of Israeli aircraft that were flying in a holding position close to Cyprus. The Syrians were not about to disclose their anti-aircraft missile capacities to Israel; and the intruders dropped the munitions and their long-range fuel tanks without pressing any attack, but returned to join the larger group still flying a holding pattern off Cyprus before all returned to Israel as a single formation."
The Turkish Air Force also operates F-15s and F-16s so if the Israeli aircraft approached over Turkish territory, it is unlikely that the Syrians could be sure of where the planes came from.
With German warships off Lebanon and a British airbase and long-distance radar station on Cyprus, any claim that NATO didn't know about these events is spurious.
If the Germans have any sense (after the USS Liberty attack by the Israelis) then the warships off Lebanon are likely to be Sachsen class air-defense frigates. These are fitted with SMART-L which is probably the most capable long-range radar in the world able to detect aircraft at a range of 750km. For such a warship, located of southern Lebanon, the entire Syrian coast and much of the Turkish coast is within range at less than 400km.
I don't know how capable the British radar on top of Mt Olympus in the Troodos range of Cyprus is, but I have seen reports a while back which suggests that it fully covers most of the Turkish, Syrian, Lebanese and Israeli coasts and someway in land.
Furthermore, I think the news today that radar on UN ships off Lebanon is disrupting Israeli satellite TV is a complete red herring. It is most likely an attempt to shut down the radar so that the Israelis can do what they want without others knowing. The only other interpretation is that the Israelis are worse than Hezbollah at handling satellite TV signals or their disruption. Hezbollah, after all, managed to keep their satellite channel on air throughout the war last year despite considerable efforts by the Israelis to jam it.