The US Navy's missile problem in the shadow of the Iran War

The US Navy's problem is not a lack of VLS cells. The real issue is the insufficiency of missile production, industrial, and logistical capacity to reload these cells when a war drags on.

The majority of the primary missiles used by the US Navy, which consists of approximately 233 combatant and 60 auxiliary ships, for land attack, air defense, and surface warfare are fired from vertical launching systems, or VLS. Tomahawk Block IV and V cruise missiles are used for land attack; SM-2, SM-3, SM-6, and ESSM missiles are used for air and missile defense, while some SM-6 and ESSM variants can be used against surface targets. Therefore, the number of VLS cells a warship possesses largely determines the maximum amount of ready-to-fire missiles it can carry. Since there is no separate main ammunition magazine on the ship for these missiles other than the VLS, every missile fired directly reduces the ship's current combat load. Empty cells cannot be reloaded from another ship while underway; the missiles must be reloaded into the cells vertically in port using heavy cranes. Thus, the fundamental problem is the ability to reload VLS cells throughout a war.

US VLS CAPACITY

Today, each of the 70 DDG-51 class destroyers in the US Navy has 96 VLS cells, each of the 3 Zumwalt-class destroyers has 80 VLS cells, each of the 17 CG-47 class cruisers has 122 VLS cells, and each of the 12 Virginia-class nuclear attack submarines has 12-40 VLS cells. In total, if we assume and accept that all of these ships—that is, 102 destroyers, cruisers, and submarines—are operational and all VLS slots are full, we arrive at a total capacity of 10,000 missiles ready for firing (an average of 98 per ship).

VLS CAPACITY OF US ALLIES

The vertical launching system (VLS) capacity of the US's primary allies is also quite limited when compared to the US. The Japan Maritime Self-Defense Force has a total of 1,000 VLS cells with approximately 16 Aegis destroyers, while the South Korean Navy has approximately 700–760 VLS cells across 17 large combatant ships. In contrast, the British Royal Navy currently has a total of 288 VLS cells in its only six Type 45 air defense destroyers in active service today.

CHINA AND RUSSIA VLS CAPACITY

When examining the modern surface fleet of China, the US's greatest naval rival, it is seen that there are 112 VLS cells per ship in approximately 10 Type 055 cruisers/destroyers, 64 in 35 Type 052D/DL destroyers, and 32 in 40 Type 054A frigates. Based solely on these three classes, China reaches a total capacity of 4,640 VLS cells across approximately 85 ships, and with the addition of other older and newer VLS-equipped classes, it reaches or exceeds a total capacity approaching 5,000. From China's universal VLS cells, primarily the HHQ-9 family of air defense missiles, YJ-18A anti-ship cruise missiles, and Yu-8 anti-submarine warfare rockets can be fired. While most Chinese attack submarines use cruise and anti-ship missiles from torpedo tubes, strategic nuclear submarines have vertical ballistic missile launchers, and it is assessed that the new generation Type 093B attack submarines have VLS capacity for cruise missiles.

Russia's anti-ship missile VLS capacity in its surface fleet is at the level of approximately 500–700 cells. When air defense VLS cells are added, the total vertical launch capacity reaches approximately 1,200–1,500 cells. However, the Russian Navy's primary long-range strike power stems not from VLS capacity, but from its Yasen and Oscar-class submarines and other submarines capable of using Kalibr and Oniks missiles from torpedo tubes. Therefore, it would be misleading to look only at the number of VLS cells when evaluating the Russian Navy's missile power.

CHANGING MISSILE LOADS

The number of vertical launcher (VLS) cells does not by itself indicate the actual ammunition load carried by a warship. VLS cells on the same ship can be filled with different missile combinations depending on the nature of the mission. A navy's peacetime deployment and its loading configuration for a high-intensity air-sea operation differ significantly from one another.

Since the primary duty of warships is to ensure their own survival, a significant portion of VLS cells is usually allocated to air defense missiles (SM-2, SM-3, SM-6, ESSM). Anti-ship cruise missiles, land-attack missiles, and anti-submarine warfare ammunition are loaded in different proportions depending on the theater of operations, threat assessment, and the objective of the mission. For this reason, two ships of the same class, despite having the same number of VLS cells, can set out on a mission with completely different missile configurations.

US MAINTAINS CLEAR SUPERIORITY IN VLS CAPACITY

Although the US Navy has fallen behind the Chinese Navy in the number of warships, it maintains a clear superiority of up to 2 times in vertical launcher (VLS) capacity. In other words, despite being behind in the number of platforms, the US has approximately twice the capacity of China to carry long-range precision-guided munitions. When the approximately 1,000 VLS cells of Japan and approximately 700 VLS cells of South Korea, two important allies in the Pacific, are added to this superiority, the total missile magazine depth of the US-led alliance rises well above that of China. However, it is not accurate to reach a definitive conclusion about the balance of power by looking only at the total number of VLS cells.

LOW COMBAT READINESS LEVEL OF THE US NAVY

According to USNI Fleet Tracker data dated July 20, 2026, only about 100 of the US Navy's total of 233 combatant and 60 auxiliary ships are forward-deployed, and of these, only about 90 are active in their mission areas. This picture shows that the US Navy's effective combat readiness level is at approximately the 30% level. While a significant portion of the ships are in the maintenance, modernization, and training cycle, others are serving in different operational areas such as the Atlantic, Mediterranean, Middle East, and Indian Ocean. Therefore, there is a significant difference between the fleet size on paper and the combat power that can actually be used. The fact that about two-thirds of the fleet is not in the operational area even during a period when a large-scale conflict with Iran is ongoing clearly reveals this difference.

Even if it is assumed that some of the ships at main bases could be rapidly prepared for duty in the event of war, at best, this rate could only reach the 50% level today. Moreover, the planned maintenance and repair program is running about seven years behind, and many of the ships in the reserve fleet to be used in mobilization are over forty years old. This is one of the most important structural weaknesses limiting the US's numerical fleet superiority.

THE US'S REAL PROBLEM: MISSILE PRODUCTION AND RESUPPLY

The most critical problem for the US Navy is not the insufficiency of the number of VLS cells, but the speed at which fired air defense and strike missiles can be reproduced and delivered to the fleet. In high-intensity naval warfare, the determining factor is not the first salvo, but the industrial production capacity that can fill the VLS cells that empty as the war drags on, the resilience of the supply chain, and the speed at which ammunition is delivered to the front. The US faces significant structural constraints in this area. The production pace of the defense industry is low; the shortage of qualified labor, bottlenecks in the subcontractor network, and problems in the supply of critical components, especially rare metals, make it difficult to rapidly increase production capacity.

At the root of this vulnerability lie the operations the US has conducted after 1990 against opponents without strong air and missile threats, such as Iraq, Afghanistan, Libya, and Syria. During this period, while priority was given to Tomahawk cruise missiles, the need for high-cost air defense systems such as THAAD, Patriot, SM-2, SM-3, and SM-6 remained limited. As a result, the American defense industry could not develop the production capacity to support a high-intensity and long-duration air-missile defense war.

According to a 2024 assessment by The National Interest, the US had procured approximately 12,000 SM-2s, 400 SM-3s, 1,500 SM-6s, and 9,000 Tomahawks by the end of 2023, while it had consumed at least 2,800 Standards and 2,900 Tomahawks in wars, exercises, and training. Thus, the approximately 17,000 missiles theoretically remaining were only enough to fill the approximately 10,000 VLS cells at the beginning of 2024 once. Moreover, after 2017, annual SM-6 production remained at the level of approximately 125 units, Tomahawk procurement gradually decreased, and there was not even room for new Tomahawk orders in the 2025 budget.

Although the Trump administration realized this structural weakness and directed the defense industry to increase production, replenishing the ammunition stocks rapidly consumed due to the Ukraine War first, and then the conflicts in Iran and West Asia, is becoming more difficult every day. As a result, in a possible Pacific war, the determining factor for the US will not be the number of warships or VLS cells it possesses, but the ammunition production capacity, resupply speed, and the industrial infrastructure that will support these to keep these ships in a continuously combat-capable state.

2027 SCENARIO AND MISSILE LOADS

Assuming that the US reaches the 80% combat readiness level it has targeted for many years in 2027 and sends all its ready combatant ships to the Western Pacific, it will have approximately 80 VLS-capable warships and 8,000 VLS cells. It can be assessed that China will reach a similar capacity with approximately 76 VLS ships at a 90% combat readiness level. Therefore, a rough balance will be formed in terms of VLS capacity in the Western Pacific. However, the US holds a significant advantage thanks to its ability to fire approximately 240 Tomahawks from underwater from 22 Virginia-class nuclear attack submarines. Therefore, although the parties approach each other in first-salvo capacity, the US's most important superiority is the invisible strike capacity to be carried out from submarines.

In contrast, air defense missiles will make up the majority of the VLS loads of American surface ships. It is highly probable that this ammunition will be rapidly depleted in the early stages of the war in the face of intense missile attacks that China will carry out from land, air, and sea. Even if the ships remain outside missile range, this time, the strike missiles used against land and ships will decrease in a short time.

MISSILES NEEDED FOR THE PACIFIC ARE BEING CONSUMED IN WEST ASIA

The US Navy's VLS-equipped Aegis cruisers and destroyers are not only operating in the Red Sea and the Eastern Mediterranean. The same ships will also form the backbone of the air and missile defense of aircraft carrier strike groups in a high-intensity war that could be experienced with China. Considering the intense ballistic and hypersonic missile threat in the Western Pacific, it can be assessed that each aircraft carrier group will need to be protected by four to five Aegis ships. This theoretically means that 40-55 VLS-capable warships will be needed for 10-11 aircraft carrier strike groups.

The SM-2, SM-3, and SM-6 missiles carried by these ships operate against different threat layers. Especially against China's DF-21D, DF-26, and DF-27 anti-ship ballistic missiles, which are assessed to have a range of 5,000-8,000 km, SM-3 and SM-6 stocks are of critical importance.

However, this ammunition, which will be needed in the Pacific, has been consumed intensively in recent years in the Red Sea, the Eastern Mediterranean, and the Iran wars. Every SM-2, SM-3, and SM-6 fired against the Houthis and Iran's missile attacks on Israel also reduces the strategic stocks that could be allocated for the Pacific. The fact that the production speed cannot compensate for this consumption turns the ammunition problem from a regional logistical issue into a strategic problem affecting American global force planning. According to US war doctrine, 2 air defense missiles are fired against an approaching air threat on ships. Therefore, a serious weakness emerges in both quantity and cost. Missiles worth millions of dollars can be spent against a hundred-thousand-dollar Houthi UAV.

Due to this pressure, the US Navy plans to integrate Patriot PAC-3 MSE interceptors into Aegis warships in addition to the existing Standard missile family. This initiative reflects not only the quest to establish a deeper and multi-layered air defense architecture but also concerns about existing interceptor stocks and production capacity against China's increasingly developing ballistic and hypersonic missile threat.

THE PROBLEM IS NOT VLS CELLS, BUT MISSILE PRODUCTION AND RELOADING CAPACITY

The conflicts that began at the end of 2023 and turned into a large-scale US-Israel-Iran war in 2026 showed that the US Navy's fundamental problem is not the number of VLS cells. The US has the world's largest sea-based missile firing capacity with approximately 10,000 VLS cells. However, what is decisive after the first salvos is the speed at which the SM-2, SM-3, SM-6, and Tomahawks that will fill the empty cells can be produced and delivered to the front. The operations conducted against the Houthis in the Red Sea, Iran's attacks on Israel, and the 2026 war have consumed a significant portion of the high-value air defense and strike ammunition allocated for the Pacific in West Asia. Thus, the strategic reserves to be used against China have begun to erode before a single missile has been fired in the Pacific.

The problem is not just the depletion of stocks, but that the production speed of the American defense industry remains behind operational consumption. The infrastructure established after the Cold War is not on a scale to support a long-duration war of attrition to be conducted simultaneously in Europe, West Asia, and the Pacific. Moreover, SM-2, SM-3, and SM-6 production lines also have to meet the orders of Japan, South Korea, Australia, and other allies. Long production and delivery times are as significant a constraint as high costs. Replacing strategic interceptors like the SM-3, in particular, can take years. Therefore, in the naval wars of the future, the determining factor will be the industrial capacity that can reload the VLS cells that empty as the war drags on, rather than the number of missiles that can be fired on the first day.

THE REAL PROBLEM IS NOT FIREPOWER, BUT SUSTAINING IT

Ensuring the uninterrupted fulfillment of the ammunition, fuel, and maintenance needs of task forces thousands of nautical miles away is a prerequisite for warships to maintain their combat effectiveness after the first salvo. Another problem for the US Navy in all operational areas is the ability to deliver ammunition, fuel, spare parts, and reinforcements to the front across thousands of nautical miles. The difficulties experienced in shipments to Europe during the Russia-Ukraine War have shown how fragile Pacific logistics could be in a war with China. Similarly, American warships that have not been able to enter the Gulf from the Strait of Hormuz since February 28, 2026, have had to make their supplies for fuel and food from floating units, while they have had to go to Guam or Indian ports for missile resupply.

The US-flagged merchant fleet is limited to approximately 200 ships. The Military Sealift Command fleet is also not of a size to support a high-intensity war to be conducted on multiple fronts simultaneously. In contrast, China's merchant fleet of approximately 5,500 ships could create a significant logistical reserve in wartime.

According to Pentagon planning, approximately 90 percent of military loads in a China war will be transported by sea. However, the distances in the Pacific are much longer than in Europe, and supply lines are much more open to missile, submarine, air, and surface threats. Aegis destroyers will need to be allocated for convoy escort to protect logistics ships, and the same ships will also be needed for aircraft carrier defense and ballistic missile defense missions. While forward bases like Guam are critical in terms of ammunition resupply, they are within the range of Chinese missiles. Resupply from bases further back will lengthen lines and increase dependence on sea transport. Virginia-class submarines and surface ships will have to return to safe ports after consuming their first missile loads, and even the completion of their second full loading will not be guaranteed.

Therefore, the US's superiority in the number of VLS against China is not decisive on its own. The outcome of a Pacific war will depend more on the safe delivery of fuel, ammunition, and reinforcements to the transoceanic front over months than on the firepower of the first day. The US Navy's real challenge is not to acquire more ships or VLS cells, but to rebuild the production and logistical architecture that will sustain this firepower.

CONCLUSION

The 2026 Iran War revealed not only the extent to which air and naval operations but also the US's precision-guided munition stocks are being strained. According to open-source estimates, the US Navy used hundreds of SM-2, SM-3, SM-6, ESSM, and Tomahawk missiles from its ships and Aegis combat systems; in addition to this, destroyers and cruisers in aircraft carrier strike groups conducted intense air defense warfare to prevent Iranian ballistic missiles, cruise missiles, and UAV attacks.

While it was estimated that there were approximately 1,160 SM-6s, 410 SM-3s, 3,100 Tomahawks, and thousands of ESSMs and SM-2s according to open sources before the war, it is assessed that a significant portion of these were consumed in the war. Unit costs are at the level of approximately 28.7 million dollars for SM-3, 15.5 million dollars for THAAD, 5.3 million dollars for SM-6, 3.9 million dollars for Patriot, 2.6 million dollars for Tomahawk, and approximately 2 million dollars for ESSM Block 2. More importantly, replacing this ammunition is a serious time problem beyond a money issue. Considering the current production capacity, it is seen that replacing the used ammunition requires delivery times ranging from 3.5 to 5.5 years, and production bottlenecks, especially in systems that form the backbone of naval air defense like SM-3, SM-6, and Tomahawk, seriously strain the US's stock sustainability for long-duration high-intensity naval wars. This picture shows that in a large-scale conflict that could be experienced in the Pacific or another front in the future, ammunition stocks have become a strategic element at least as decisive as the number of platforms.

This strategic reality was concretely revealed with US President Donald Trump's decision to stop attacks on July 25, 2026, after a 13-day intense air operation against Iran. As reported by the New York Times, the rapid depletion of Patriot air defense missile stocks, the increasing vulnerability of American bases in the Gulf, the risk of the regional war growing, and the fact that the operations strengthened social solidarity instead of producing the expected political result in Iran were influential in the decision. In other words, Washington reduced the operational tempo not because it lost its military superiority, but because it saw that the ammunition, logistical, and industrial cost of a long-duration high-intensity war was incompatible with strategic goals. This decision once again showed that success in modern naval and air wars depends not only on advanced weapon systems but also on the industrial capacity that can produce them sustainably and deliver them to the front. The factor that will be decisive in the great power competition of the 21st century is not having the most powerful fleet, but being able to keep the production, logistics, and ammunition ecosystem that can fight for the longest time alive.

The great naval wars of the 21st century are leaving behind the platform-centered thinking of the Cold War. What is decisive now is not how many aircraft carriers, how many destroyers, or how many VLS cells one has. The real decisive factor is whether one has the industrial infrastructure that can reload the VLS cells that empty as the war drags on, the logistical power that can deliver this ammunition to transoceanic fronts, and the economic capacity to conduct sustainable operations on more than one front simultaneously. The Iran and Houthi crises have shown that the US having the world's most powerful navy is not enough on its own. For China, on the other hand, every American air defense missile and Tomahawk missile consumed in West Asia is ammunition missing from the arsenal of a war that has not yet begun in the Pacific.