The two countries differ markedly in the size and capabilities of their forces. Iran has the larger military, with two forces — the Islamic Revolutionary Guard Corps (IRGC) and the Artesh regular military — composed of complementary air, naval, and land branches. The Artesh has an estimated 350,000 active-duty soldiers and controls most of Iran’s more sophisticated conventional capabilities, especially in the air and maritime domains. By comparison, the IRGC, with an estimated force of 125,000, has maintained a focus on asymmetric warfare but also oversees Iran’s growing unmanned aerial vehicle fleet and strategic ballistic missile programs. Additionally, through its special forces division, known as the Quds Force, the IRGC commands Iran’s foreign military operations and relations with client allies, such as in Syria and Iraq.
Since the 1980s, intermittent sanctions and political pressure from the United States have severely degraded Iran’s ability to procure military technology and weapons from other countries, which has made some of its military capabilities relatively outmoded and weak. Iran’s defense spending (around $12.3 billion in 2016) is modest compared with Saudi Arabia’s as one of the top defense budgets in the world ($63.7 billion in 2016 and $69.4 billion in 2017), and its defense technology generally falls well below that of other regional states. Iran’s air forces fly dated platforms, such as F-5 and F-14 Tomcat variants, which have been updated domestically from aircraft inherited from the pre-revolution Pahlavi state, but struggle with intermittent inoperability. Similarly, Iran’s mechanized armor is mostly a hodgepodge of pre-1979 U.S. stock (such as the M60A1) and older Soviet tanks (such as the T-72S) procured from Russia during the 1990s.
Unable to update its military capabilities, Iran has instead invested in other areas, especially ballistic missiles, to provide a competitive edge with its neighbors. Its ground-to-ground ballistic missile variants, such as the Zolfaghar (435-mile range) and Shahab-3 (994-mile range), could potentially targetstrategic infrastructure and population centers well within Saudi territory. Those ranges and the large stockpile Iran has amassed have made ballistic missiles Iran’s core strategic deterrent. Iran showcased that capability in June 2017 when it fired six Zolfaghar missiles at Islamic State-held territory near the Syrian city of Deir Ezzor, some 435 miles from the launch points in western Iran. Beyond that hard deterrent, the IRGC’s investments have concentrated on developing less expensive platforms that can challenge adversaries through asymmetrical tactics. Foremost in this regard is the IRGC Navy’s large fleet of fast attack crafts, which includes various types of small speed boats that can be armed with 107 mm rockets, heavy machine guns, and anti-ship cruise missiles, or loaded with explosives and used in kamikaze-style strikes. These boats, along with its large stockpile of naval mines, are the IRGC’s primary offensive tool against maritime adversaries in the maritime domain.
The Saudi military is smaller but better armed. Saudi Arabia’s primary military land, air, naval, and missile forces fall under the command of its Ministry of Defense. Combined with auxiliary forces in the Saudi Arabian National Guard, Royal Guard, and the Ministry of Interior’s border defense force, the Saudi military is estimated to have around 250,000 active-duty personnel. Its chief strengths lie in airpower and air defense. The Royal Saudi Air Force possesses several squadrons of F-15C/D Eagle and F-15 Strike Eagle fighters, along with three squadrons of Tornado multirole aircraft, and 72 Eurofighter Typhoon attack aircraft. The Royal Saudi Air Defense Forces have similarly impressive capabilities, focused mainly on U.S.-supplied Patriot missile batteries concentrated around critical infrastructure, military bases, and population centers. Saudi Arabia also has a small but perhaps growing stockpile of ballistic missiles. Its Strategic Missile Force is believed to possess dozens of aging liquid-fueled Chinese DF-3 medium-range missiles (2,485- to 3,100-mile range) and possibly some solid-fueled DF-21 medium-range missiles (1,050-mile range) as well.
Of course, capabilities are one thing, effectiveness on the battlefield another. Experience matters and can help a military identify its weaknesses and develop strengths. Both countries have had recent experience in combat, albeit in different ways and to different extents.
Much of Iran’s military know-how was developed during the nearly eight-year Iran-Iraq War, where it fought against a technologically superior adversary with far greater international backing. If the Iran-Iraq War taught Iran’s armed forces how to survive and make limited gains through asymmetrical tactics, the post-2011 experience of the IRGC and its client allies (such as Lebanese Hezbollah and various Iraqi militias) in the Syrian, Iraqi, and Yemeni conflicts has helped it develop further in terms of command and control, integrated operations, and ground offenses. Although Iran and its clients have been inseparable from the ground successes in both Syria and Iraq, those advances have been paved by foreign air power (by the United States in Iraq and Russia in Syria). Without the support of such air power, it is doubtful that Iranian-led forces would have made any serious gains against Syria’s rebels or the Islamic State. Further, they have relied on artillery bombardments, which essentially flattened the adversarial-held population centers before they were retaken.
The Saudis have comparatively less combat experience. In 1991, Saudi and Kuwaiti forces struggled to defeat an Iraqi tank column that had occupied the Saudi town of Khafji. They ultimately prevailed with U.S. support, but the battle exposed the inexperience of the Saudi military. In a precursor to the current conflict in Yemen, Saudi forces intervened across the southern border in 2009 in support of the Yemeni government’s war against the Houthis. The Saudi campaign, which included Jordanian and perhaps Moroccan troops, lasted only a few months and concentrated on the bombing of Houthi positions near the border. Despite retaking some strategic high ground along the border, the aerial campaign had only a small impact on the overall ground war. That limited track record clearly did not prepare the Saudis for the current war in Yemen. But the longer the current war continues, the more experience the Saudi military will gain.
Thus, as crude as it might be to think of the ongoing Yemeni conflict as military practice for the Saudis, given the brutal toll it has had on civilians, that is precisely what it has been. Without dismissing Saudi’s legitimate national security concerns about Yemen, or minimizing the extensive suffering the war has caused, the conflict has offered an opportunity for the Saudis (and the Emiratis) to test their air and land capabilities in combat and to work on integrated joint operations.
Still, the campaign has only had limited success. Although the Saudi-led coalition was effective early on in pushing pro-Houthi forces out of positions in the south, it has struggled to make advancements in the north. This is especially true regarding the capital, Sanaa, where Saudi Arabia’s extensive bombing campaign hasn’t led to corresponding gains on the ground. There have also been serious questions posed about Saudi Arabia’s targeting ability and its capabilities in intelligence, surveillance and reconnaissance, particularly in the face of the severe civilian toll the bombing campaign in Sanaa has had.
Given their respective capabilities and recent experiences in combat, both countries have strengths and weaknesses, but neither has a clear advantage over the other. Saudi airpower would enable it to maintain dominance in the skies in any conflict with Iran. It could likely strike Iran’s critical infrastructure and military bases along the coast with air-to-ground missiles, if not penetrate Iranian territory more deeply. Iran, for its part, would likely be able to achieve primacy in the maritime domain, especially in the Persian Gulf, where its fast attack craft, diesel submarines, and mine-laying vessels could be used to target Saudi shipping, naval ships, and ports. Iran could also strike Saudi strategic infrastructure and population centers with ballistic missiles. Although Saudi Arabia’s Patriot missile defense systems would likely reduce the effectiveness of such strikes, it is unlikely that those defenses could prevent all strikes from landing, especially were Iran to fire missiles in salvos.
If a Saudi-Iran conflict were to occur in a vacuum, the war would not be about territory or regime change by force. Neither side can take the fight across the Persian Gulf, much less seize and hold strategic areas in adversarial territory. The conflict would be about inflicting damage to both punish the other side and compel it to cease hostile behavior. While the Saudis — with their superior air power, access to foreign military technology, and far greater wealth — might be better situated to endure such a conflict, if not impose greater costs on the Iranians, the Islamic Republic has less to lose and has shown an ability to withstand years of warfare against greater powers.
However, it is unlikely that such a conflict would involve only those two parties and not grow to involve other states. Iran lacks state allies (except for Syria, of course, which is hardly a state now), but it does have a robust, transnational alliance with nonstate clients in Lebanon, Syria, Iraq, and Yemen. Groups such as Lebanese Hezbollah or Asaib Ahl al-Haq in Iraq would almost certainly support Iran in such a conflict, including by targeting Saudi nationals in their own countries, but they couldn’t attack Saudi territory militarily with any degree of effectiveness.
Saudi Arabia, however, has a strong alliance with Arab states (especially the United Arab Emirates and Jordan) and with the United States. Were such a conflict to occur, it is difficult to imagine that the United States would not become involved in one way or another in support of the Saudis. Although Iran could certainly raise the costs of American involvement by targeting U.S. naval vessels in the Persian Gulf directly or by targeting U.S. forces and nationals in other countries by proxy, Iran would have to balance such actions with the risk of drawing the United States into a more extensive war.
Thus, the possible involvement of the United States would be the x-factor in any potential conflict between Iran and Saudi Arabia. Even if the two states are quite evenly matched, the military power that the United States could bring to bear would heavily tilt a conflict in Saudi Arabia’s favor. In other words, it would be incredibly risky for Iran to court escalation with Saudi Arabia. Such a conflict likely wouldn’t involve just Saudi Arabia, and Iran does not possess the capabilities to outlast a coalition military effort against it. Afshon Ostovar for Foreign Policy