Is A Major Attack On Syria Feasible? Or Are Russia's Area Denial Forces Just Too Strong?

"As a result a Western attack, should it occur, would most likely be limited to a symbolic strike as per April 2018"

By Military Watch: With the United States, Britain and France all reportedly making preparations to launch a major offensive against Syria, and threatening use of force on a scale far larger than that of the attack carried out in April 2018, Russia has notably responded by moving naval assets to the Mediterranean and deploying its warships in defensive positions to deter a potential second Western attack.
While Russia has previously tolerated Western interventions against Damascus on a small scale, namely token missile strikes initiated with prior warning which were further blunted by Syria’s own air defences, a larger strike which could have a significant impact on the outcome of the war - at a time when Damascus’ forces and those of its allies prepare for a major ground offensive against the Jihadist held province of Idlib - could well cross a red line which would lead to Russian intervention on the side of its Middle Eastern ally.
To be able to deter a Western attack however, Russia will need to demonstrate that it has a credible chance of protecting Syria against the combined firepower of its adversaries despite the far smaller size of its forces in the country
- which pale in comparison to the massive Western military forces deployed throughout the Middle East and the U.S. and possibly French carrier strike groups which are likely to participate in an attack.
For Russia’s naval contingent in Syria to have a chance of deterring the Western fleets, it will need to rely on two critical assets - support from ground based aircraft and missile systems operating from Syrian territory itself, in some cases from as far as Russia’s own territory, and extensive use of asymmetric weapons systems which will leave Western assets such as warships, fighters and bombers vulnerable despite their numerical advantage.
While Russia’s sole aircraft carrier is poorly suited as an asset for long range power projection, and is nevertheless currently undergoing a refitting and unavailable for frontline service, the country has an arguably far more valuable asset - Khmeimim airbase in Syria’s Latakia province. While modern Western carriers lack high performance air superiority fighters, the last of these having been retired by the United States Navy shortly after the Soviet Union’s collapse in favour of lighter unspecialised multirole aircraft, Russia’s Air Force contingent relies heavily on specialised heavy combat jets such as the Su-35, Su-30SM and Su-27SM air superiority fighters and Su-34 strike fighters.
The first three of these enjoy considerable advantages in speed, operational altitude, engagement range, range and manoeuvrability over their counterparts in the U.S. Navy allowing them to protect Russian warships and Syrian assets from air attack even against enemy air contingents many times their size.
The Su-34 meanwhile, as an advanced long range ship hunter armed with missiles such as the Mach 3 Kh-41, the Mach 3.5 sea skimming Kh-31A and the 300km range Kh-35U and P-800, can pose a major threat to hostile warships at considerable distances from Syrian coast - with missiles designed to evade the latest and most capable air defence networks fielded by the U.S. Navy. 
Russia’s fighter contingent in Syria is currently estimated to consists of four Su-27SM, eight Su-30SM, four Su-35 and eight Su-34 jets - alongside the lighter and less specialised MiG-29SMT and older Su-24M4 strike fighter. Four Su-57 fifth generation air superiority fighters have also deployed to the theatre, though whether these assets are fully combat ready and armed with K-77 missiles needed for air to air engagements, or whether they were deployed solely for combat testing, remains in unknown.
Russian fighters are backed by a number of the Air Force’s most formidable support assets - including A-50U AWACS platforms, which serve as a highly capable force multiplier able to coordinate strikes by combat aircraft and warn against incoming attacks using a powerful Vega-M radar.
Other supporting air assets fulfilling complementary roles to the fighter fleet include Il-20M1 electronic radar reconnaissance aircraft and the new Tu-21R electronic intelligence aircraft - all of which are key to enhancing the combat potential of the fighter contingent deployed to Syria. 
Alongside a sizeable contingent of elite fighter jets which will be more than sufficient both to prevent Western forces from gaining air superiority while threatening Western warships far from Syria’s coasts, thus providing critical air support to the naval contingent in the Mediterranean, Russia also fields a number of other support assets which are each in their own right potential game changers in the event of conflict.
While the risk of open conflict between the Western powers and Russia remains unlikely, retaining a viable military contingent is critical to Russia’s ability to deter a potential Western offensive - as should its forces be perceived to be too weak to protect Syria or themselves from a Western strike the prospects for the Western powers to follow through on threats to strike Syrian targets remains considerably more likely.
Accompanying the fighters deployed to Syrian territory are state of the art air defence systems which are capable not only of denying hostile aircraft access to Syrian airspace but also, in the case of longer ranged platforms, of targeting enemy aircraft well beyond Syria’s borders whether over the Mediterranean or over the territory of neighbouring states.
While the short ranged systems deployed remain unknown, with only the presence of the Pantsir-S1 confirmed, the long ranged S-300VM and S-400 were deployed to Syria from 2015 in response to a Turkish air attack on a Russian strike fighter. The S-400 remains unparalleled in its capabilities and well within its limits to target Western combat jets as soon as they depart from their carriers in the Mediterranean. 
A single S-400 battalion is capable of engaging up to 80 targets simultaneously with up to 160 missiles, and with these missiles travelling at hypersonic speeds and striking with high degrees of precision the weapons system can effectively eliminate any known formation of attacking combat jets in little over a minute even at extreme ranges.
These ranges are unrivalled by any other air defence system in the world, with the S-400 deploying the 400km range 40N6 missiles, the 250km range 48N6DM/48N6E3 and the 200km range 48N6E2. The weapons platform can target hostile aircraft at altitudes as low as 5 meters - just hovering over a carrier deck - and was designed to target the U.S. Air Force’s elite radar evading F-22 Raptors, making the U.S. Navy’s slower, less manoeuvrable, lower flying and non stealthy F-18 jets easy targets. With the S-300VM specialised in a missile defence role, and shorter ranged air defence systems forming additional layers to the defence system alongside the S-400’s own medium and short ranged 9M96, 9M96E2 and 9M96E missiles, Russia will be able to effectively seal Syria's airspace and protect its own naval assets from a Western air attack should it choose to intervene. 
Another valuable asymmetric asset deployed to Syria is the Mi-8MTPR-1 electronic warfare helicopter, designed to blind enemy warplanes and missiles up to 400km away, which serves in a highly complementary role to the Russian air defence systems. The helicopter is equipped with a Rychag-AV radio electronic warfare system, one of the world's most powerful jammers, which provides Russia with an invaluable asset both to protect its forces and to launch counteroffensives against Western assets.
Alongside assets deployed to Syria itself, the Russian Air Force can also rely on a number of long ranged supersonic aircraft which can quickly respond to any threat to its forces from Russian territory itself - deploying some of the country’s latest long range munitions at standoff ranges. The Tu-160 and Tu-22M bombers and MiG-31 interceptors in particular are highly valued for both their high speeds and payloads and for their ability to target enemy warships in the Mediterranean from bases in Russia.
The MiG-31, armed with Kh-47M2 ‘carrier killer’ Kinzhal hypersonic missiles - platforms travelling at over five times the speed of sound and capable of evading any existing anti missile system, can disable even the largest of warships at extreme ranges with a single strike. The Kinzhal’s range allows Russian aircraft circling above Moscow to strike Western carriers and destroyers in the Mediterranean, with the missiles making use of their long range and hypersonic speeds to make impact just minutes after firing.
Alongside the MiG-31, the Kh-32 cruise missile deployed by the Tu-22M, a weapon designed specifically to neutralise Western carrier strike groups at extreme ranges, is also lethal as an anti ship platform and can be deployed within minutes by bombers stationed in Russia against targets in the Mediterranean. After climbing to altitudes of 40km the missile descends to extremely low altitudes, often as low as five meters above water, before impacting its target at several time the speed of sound. The missile is extremely difficult to detect, leaving enemy warships with a reaction window of ten seconds or less, and several of these 500kg munitions can be carried by each Russian bomber. 
Other key assets deploy by Russia which are set to have a game changing impact on a potential conflict in Syria include Tu-142MK maritime reconnaissance and anti submarine warfare aircraft, two of which arrived at Hmeimim airbase in Syria’s Latakia province in early September 2018 shortly after reports emerged of Western submarines sailing near Syrian coasts.
These long ranged reconnaissance aircraft, designed to operate against submarines in far deeper and wider waters than the Mediterranean, pose a considerable threat to hostile submarines at sea and are an effective complement to the numerous assets deployed to target hostile surface ships. The far greater prevalence of advanced high speed anti ship missile systems among Russia’s own surface warships and submarines, prime examples being the Kalibr and P-800 which impact at over Mach 3, is a further asymmetric asset working in the favour of the outnumbered Russian contingent.
Ultimately while it is critical to note the extremely low likelihood of a intentionally initiated direct clash between Russian and Western forces over Syria, the strength of Russian assets deployed there and their ability to hold their own and pose a serious threat to Western warship and aircraft does much to deter a Western attack - or at the very least deter such an attack from crossing any of Moscow’s red lines and having a meaningful impact on the outcome of the conflict.
As a result a Western attack, should it occur, would most likely be limited to a symbolic strike as per April 2018 - with the strength of the Russian military and its commitment to protect its ally and win a decisive victory in the Syrian conflict serving as a serious constraint on the Western Bloc’s freedom to intervene. 

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