Even with the skies above Syria effectively closed off to the Israeli Air Force due to the sudden emergence of an S-300 threat, the chances are that Israel will not end its strikes against Iranian and Iranian-related targets across the Levant; instead bombing operations will recommence in Lebanon and probably be extended into Iraq.
The almost endless rhetoric of Israel and the US about Iranian entrenchment in Syria aside, the reality stands that most of Iran’s deployment of extra-territorial operations forces (i.e. Quds Force) and the armed groups (such as the majority of PMF factions) that it backs are located in Iraq.
The US position on this reality has always been a confusing one, for an Iranian-backed group in Iraq will be considered a coalition partner (although this is possibly subject to change under the Trump administration in the future), yet once it crosses into Syria, it conveniently becomes a threatening “Iranian militia” that justifies America’s continued presence the country.
Israel, however, has never discriminated on this matter. To them, an Iranian or Iranian-related force or military asset is subject to attack once it exits Iran’s western border. Until the Russian closure of Syrian airspace in late September this year and Russia’s provision of S-300 systems to the Syrian military, Syria proved the ideal place to intercept Iranian and Iranian-related as well as Syrian government targets. After all, the country is involved in a multi-factional war where the air forces of several nations (including Syrian, Russian, US and sometimes Turkish) are active and, also, airstrikes conducted by Israel west of the Euphrates require virtually zero coordination with the US-led Coalition (greatly increasing official deniability).
Furthermore, and for the record, many Syrian sources believe that many of Israel’s strikes target the Syrian military and not Iranian and Iranian-related targets; this belief is justified, as indeed, Israel has targeted Syrian military forces and assets without provocation. At the same time, it is also true that Iranian and Iranian-related forces and assets in Syria are also targeted by Israel.
The technical difficulties for Israeli deniable air operations in Lebanon is that there is no war, and it is a given fact that any airstrike that takes place will have been conducted by Israel. To bomb targets in Iraq means complete coordination with the US-led Coalition and although the US will likely not protest an Israeli request, it will nonetheless release an official statement confirming that a given strike was done by Israel (this being done in order to avoid disgruntled Iranian-backed groups turning against US advisor forces on the ground in Iraq).
In any case, despite these ‘technical’ difficulties, for Israel bad PR is much more preferable than losing aircraft and pilots during an operation (which has now become a seriously increased risk in regards to Syria whose armed forces now possess two dozen S-300 systems).
Should Israel choose to maintain its military policy of actively hunting down what it believes are Iranian and Iranian-related targets operating outside of Iran – which it will almost undoubtedly do – then it will most likely choose to exchange operational deniability for maintaining its high degree of operational safety and begin intercepting convoys and bases in western Iraq as well as recommence missions in Lebanon.