Why the Iranian Purchase of the S-300 Should Worry the Gulf States

Saudi Arabia’s decision to intervene militarily in Yemen against Iranian-backed Houthi rebels has raised regional tensions to a boiling point. In a cold war between Iran and Saudi Arabia that is growing increasingly hot, the move by Russian President Vladimir Putin to lift the ban on the sale of S-300 missiles to Iran has come at just the wrong moment.

S-300PMU-1, known as SA-20 in NATO parlance, is a long-range and highly capable surface-to-air missile (SAM) system which can target both high-performance military aircraft as well as ballistic and cruise missiles. Its range of 150 km against aircraft targets would give Iran a weapons system capable of holding potentially hostile aircraft at threat far beyond its own borders.

Under most combat conditions the S-300 can threaten modern combat aircraft that do not have very low observable (VLO) or stealth technology –  Russian sources claim that the S-300PMU-1 even has limited capabilities against stealth aircraft, but since no S-300s are known to have been fired in anger, let alone against VLO or LO designs, it is impossible to verify such claims.

There is also the more modern S-400 – a far more advanced development of the S-300 line which comes with a particular focus on detecting and tracking VLO designs at long range, suggesting that the preceding S-300PMU-1 and PMU-2 were considered inadequate for this task. Iran and Russia have raised the possibility of an S-400 sale in addition to the S-300PMU-1. However, Iran’s armaments relationship with Russia is complicated by Moscow’s own sales to Riyadh. Following Saudi engagement with Russian defence giant Rosboronexport, the potential for an S-400 sale to Iran was undermined by the Saudi promise of $4 billion for Russian air-defence equipment, although no deal was ever confirmed between Riyadh and Moscow.

Visualising the Threat

To understand better what the S-300 sale might mean for regional security – and why it is that the Kingdom of Saudi Arabia views the potential Russian sale in such a threatening light – it is useful to highlight four potential Iranian deployment points for the missiles, and discuss their potential implications.

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As can be seen from the diagram, sites based in Abadan, Lavan Island, Abu Musa and Sirik significantly change the strategic environment, altering threat levels for both military and civilian aircraft alike. A site based in the vicinity of Abadan offers total coverage over Kuwait City as well as the Ali Al-Salem and Ahmad Al-Jaber airbases. Additionally, popular air corridors used by international carriers through the Gulf could be effectively closed should Iran so wish. Rerouting European flights over Saudi Arabia might provide an answer to this conundrum, but Indian Ocean routes would be far more heavily affected.

Placing missiles on Lavan Island would provide penetrative coverage over Qatar’s north dome gas field and again pose significant threats to civilian airliners using the Gulf as a thoroughfare. Furthermore, linking up with sites on Abu Musa would afford double coverage of strategically important Iranian footholds deep into the Gulf, which would strengthen Iran’s ability to operate in the Gulf under air cover.

Using Sirik would provide a significant boost to Iran’s strategic position in the Strait of Hormuz. Any attempt to prevent Iran from closing the Strait would be made far more difficult, primarily because the first response would traditionally come from non-stealthy US naval and Western air power which would be severely threatened by the presence of an Iranian S-300 system in close proximity to the Strait.

The most dangerous potential location – and the most likely to invite an immediate retaliatory response and trigger a wider conflict – would be the position of a system on the Iranian-occupied island of Abu Musa, which is also claimed by the UAE. The missile system’s range would easily cover the Airbases of Al-Minhad and Al-Dhafra, as well as the oil fields of Zakum and Shariqah – not to mention all of the UAE’s major population centres and airports. The deployment would represent a huge strategic risk for the UAE.

Implications for Operations in Iranian Airspace

To operate against Iranian targets covered by S-300 batteries, Gulf Cooperation Council (GCC) air forces would require extensive electronic-warfare support in terms of tracking, jamming and suppresion capabilities. They are unlikely to possess the requisite level of technical capabilities or experience in high-level suppression of enemy air defences (SEAD) operations without direct US military support.

An optimum package for S-300 suppression at present would likely include US Navy EA-18G Growlers for brute-force jamming; RC-135U Combat Sent and RC-135V/W Rivet Joint aircraft for long-range signals intelligence and radar location; and saturation by submarine-launched Tomahawk missiles and F-22 Raptor and B-2 Spirit stealth aircraft for direct kinetic strikes. In addition, AWACS and Joint-STARS battle management and co-ordination assets would be required for the complex task of managing the large number of cross-domain platforms.

Currently, there exists no basic capacity outside of the US for an operation which would ensure a successful suppression of an Iranian S-300 capability without incurring substantial losses. The US Air Force also possesses the long institutional experience required for SEAD operations, and multiple VLO assets (including VLO surveillance UAVs such as the RQ-180) which would be able to either bypass S-300 batteries altogether, or at least get close enough to them – without being tracked – to destroy or suppress them, and relay targeting information for stand-off attacks by other assets.

However, an operation like this would take time to organise and mount. The US Navy’s carrier air groups on regular rotation in the Persian Gulf would be much more vulnerable to an S-300 threat since the F/A-18E/F Super Hornet and EA-18 Growler are not stealthy, although the Growler is a formidable jamming asset in its own right.

Policy Responses

While the Arabian Gulf States could continue to prosper following an S-300 deployment to Iran, the region’s fragile politics mean that it may be impossible to withstand the change in power balance that such a deployment brings. External intervention in the form of extended deterrence guarantees to the Gulf States from the US, UK and France would likely be all that stands between the two sides and war. Furthermore once in place, any operation to take out the systems is likely to be costly. The US, UK and their Gulf allies would need to carefully weigh up the risks of removing the threat entirely, or else learn to live with a strengthened Iranian hand across the Gulf.

Should the Russia complete the sale of its S-300 system to Iran, this would likely result in a number of procedures quickly being put into place. The Gulf States would be looking for immediate reassurance that Iran would not be able to use this cover to dominate the Gulf. Probable US responses would be to increase deployments of the US Air Force’s scarce F-22 Raptor stealth fighters to the region, and potentially to conduct ‘training sorties’ for B-2 Spirit stealth nuclear and conventional bombers near Iranian airspace as a show of force. Conversely, however, the US might also be less inclined to use its stealth aircraft in proximity to Iran’s airspace on a regular basis for fear of giving Iran too much information on the extent to which its S-300s can detect these assets under certain circumstances.

Furthermore, an Iranian S-300 capability would certainly strengthen the demand and case for GCC nations to be allowed to purchase the stealthy and strike-oriented F-35 Joint Strike Fighter which, up until now, has been refused by the US. The UAE and Qatar are also likely to follow the Saudi lead in purchasing advanced stand-off weaponry such as BAE Systems Storm Shadow, to counter an Iranian long range S-300 threat. But, as ever, the proliferation of such advanced offensive weaponry could further destabilise an already dangerous flashpoint.

Michael Stephens
Research Fellow for Middle East Studies, RUSI
Twitter: @MStephensGulf

Justin Bronk
Research Analyst in the Military Sciences Programme, RUSI
Twitter: @justin_br0nk