In the usually quiet Negev desert, the silence of the night was shattered by violent explosions in the city of Dimona, near the most sensitive site in the only nuclear arsenal in the Middle East, and then again in the streets of Arad, east of Beersheba. It was a new kind of Iranian escalation, carried out in response to the joint Israeli American strike on Natanz, where a major Iranian nuclear facility is located. In Dimona, an Iranian missile evaded the Iron Dome and landed around 20 kilometres from a nuclear research centre. In Arad, Iranian projectiles struck and destroyed more than eight residential buildings.
Within hours, around 200 Israelis were wounded. Ambulances lined the streets, and hospital beds filled with casualties. The significance of the strike did not lie only in the scale of destruction and injuries, but in what it revealed about Iran’s ability to violate Israeli airspace and penetrate layered defences to reach politically and militarily fortified environments. The central question is this: how did Iranian guidance systems evolve to a point where their missiles have become more accurate and more capable of manoeuvre in the current war?
Modern missiles are no longer simple projectiles launched into the upper atmosphere along a ballistic arc before descending on a target hundreds or thousands of kilometres away. They are guided weapons, equipped with systems that function like electronic minds, capable of identifying their own position and correcting their course in flight to reach a designated target.
The Core of the Answer: Guidance
The simplest answer can be summed up in one word: guidance.
Modern missile guidance systems include sensors and onboard computers that measure a missile’s movement and direction, compare that information to the intended path, and then send commands to engines or control surfaces to adjust the course whenever the missile deviates.
To understand this, imagine driving to a destination while relying on a navigation app linked to GPS. The app constantly tracks your location and alerts you whenever you drift off the correct route. Missile guidance performs a similar function. It uses internal or external data to determine where the missile is and then corrects its trajectory toward the target.
The end result is greater strike accuracy and a much lower margin of error, turning missiles into strategic weapons capable of hitting a specific installation or military objective with far greater precision.
From Scud B to Inertial Guidance
During the Iran-Iraq War in the 1980s, Iranian cities were subjected to intense Iraqi missile attacks using Soviet Scud missiles. At that stage, Iran did not possess the infrastructure needed to develop guided missiles or even advanced ballistic missiles. Its initial response was to import ready made missiles such as the Scud B.
These missiles lacked advanced guidance systems. Their circular error probable, or CEP, reached roughly one kilometre or more at a range of around 300 kilometres. In practical terms, this meant they would strike the general area of a target rather than the target itself with accuracy.
To simplify the idea, imagine a circular target board with the real objective at its centre. If you fire 100 arrows, not all will hit the bullseye. They will scatter around it. CEP refers to the radius of a circle drawn around the target within which around half the arrows, or 50 out of 100, are expected to land. If a missile has a CEP of one kilometre, this does not mean it always misses by exactly one kilometre. It means that, after a large number of launches against the same target, around half will fall within a circle with a radius of one kilometre, while the rest may land outside it, sometimes much farther away.
This limited accuracy made such missiles useful mainly as instruments of terror. They were directed at cities and large population centres rather than precise targets.
By the end of the war in 1988, the first signs of indigenous Iranian missile production emerged with the launch of a locally produced missile with a range of around 130 to 160 kilometres. It resembled advanced rocket artillery more than a guided missile, and it lacked sophisticated guidance. Still, it marked the first step toward building domestic expertise.
At the same time, Iran sought external technical support. In the late 1980s and early 1990s, Tehran signed scientific and military agreements with China and North Korea to acquire the knowledge needed to develop missile technology.
American sources indicate that China supplied Iran in 1996 with dozens of guidance systems and electronic components, including gyroscopes, accelerometers, and computer units. These are the core elements of any inertial navigation system. Iran also reportedly received testing equipment and components for advanced radar systems. This support proved critical because it allowed Iranian engineers to overcome the major obstacle of lacking experience in precision guidance technologies.
What Is Inertial Navigation?
Inertial navigation is essentially a method that allows a moving object, such as an aircraft, missile, or drone, to determine its position, direction, and speed without constant reliance on satellite signals.
The object senses its own movement and then uses calculations to work out where it is. The process begins from a known starting point, meaning an initial location and direction. From there, sensors record every small change in movement, second by second. If gyroscopes detect a turn, and accelerometers register an increase in speed or a shift in direction, the onboard computer integrates these changes and calculates their cumulative effect. From this, it determines the object’s current location.
This can be compared to a person walking blindfolded inside a room. If that person knows they started at the door, then walked forward several steps, turned, and continued a certain distance, they can estimate where they are even without seeing. Inertial navigation does something similar, but with electronic precision and rapid calculation.
The importance of this system lies in its independence from the outside world. It remains useful when satellite navigation signals are disrupted or jammed, as often happens in electronic warfare or complex military environments. That is why it is a basic component in many systems that need to keep navigating even after losing satellite contact.
But inertial navigation has a known weakness. Any small measurement error can accumulate over time. Because the computer constantly adds up small changes, even a slight deviation in a gyroscope or accelerometer reading can produce a significant gap between the calculated and actual position after some time. For this reason, inertial navigation is often integrated with satellite based guidance.
Iran appears to have used this approach in some of its more recent missiles, including the Fateh 313, which is believed to combine inertial navigation with satellite guidance. The concept is that the missile does not rely on one source of navigation, but on two systems working together. One is internal and independent. The other provides external correction.
Yet this type of guidance is not without challenges. GPS signals can be jammed or cut off, particularly in electronic warfare settings. That is why satellite navigation is usually not used as the only guidance method, but as a correction tool that reduces the error accumulated in the inertial system during flight.
Small Fins, Big Consequences
By the early 1990s, Iran had begun establishing domestic missile production lines, drawing on imported technologies and acquired expertise. Cooperation with North Korea helped produce the Shahab missile family, with longer ranges but still based on the same limited precision inertial guidance.
The next major leap came with the Shahab 3 in the late 1990s. Based on the North Korean Nodong missile design, the Shahab 3 had an initial range of around 1,300 kilometres. It used a conventional inertial navigation system, giving it only modest accuracy, with a CEP of around three kilometres.
Throughout the first decade of the twenty first century, Iran gradually improved its missile guidance systems. Upgraded versions of Shahab 3 appeared under names such as Ghadr and Sejjil.
Sejjil was particularly important because it used solid fuel instead of liquid fuel, making it faster to prepare and launch and improving overall performance. It is also believed that Iran began during this period to introduce more precise guidance methods, including limited or experimental use of satellite guidance.
One of the most prominent examples of this evolution was the Emad missile, unveiled in 2015. Iran presented it as its first long range missile capable of precise guidance. Emad has a range of around 1,700 kilometres and was equipped with a manoeuvrable warhead and improved guidance, which reduced its margin of error compared to Shahab 3 to several hundred metres, estimated at around 500 metres.
A report by the International Institute for Strategic Studies stated that Emad had a more advanced guidance system that allowed it to control its path even during reentry into the atmosphere. This was achieved through small fin-like surfaces attached to the reentering warhead, which could move slightly left, right, up, or down, altering its direction during flight.
These fins enabled the missile to correct its path rather than continue on a fixed line. This significantly improved accuracy and gave it a better ability to hit targets than older Iranian missiles.
In this sense, Emad marked an important turning point in Iran’s missile programme. Iranian missiles had long served as tools of broad deterrence, even when their accuracy was limited. With Emad, Iran began moving into an era of guided missiles that could strike specific locations such as military bases and command centres with much greater precision.
For any military or political actor, possessing long range precision missiles makes it possible to adopt a doctrine of accurate retaliatory strike rather than relying only on asymmetric warfare or broad threats. In earlier decades, Iran’s response to provocations was more restrained because it feared sliding into a full scale war it would lose against superior Western technology. Now, Iran appears more willing to retaliate because it knows it can inflict direct pain on its adversaries.
The Age of Sensors
The last decade can be seen as the peak of Iran’s progress in missile guidance. Most of its short and medium range missiles, such as Qiam, Fateh 313, and Zulfiqar, are now highly guided. Even longer range systems such as Emad and Khorramshahr are believed to carry guided warheads or advanced control systems that significantly reduce error.
The defining feature of this period is the integration of what can be called composite guidance. This means combining more than one source of navigation, such as inertial guidance with satellite correction, and adding independent seekers or sensors in the missile’s warhead to search for the target in the terminal phase.
These independent seekers function as the missile’s eye during the final stage. Instead of merely following a pre-programmed route with inertial or satellite corrections, the missile begins using a sensor in its nose as it nears the target, searching for the objective on its own and guiding itself directly toward it.
If the seeker is radar based, it emits radar waves and then detects their reflection from the target, allowing it to identify and track it. This is particularly useful against ships or large targets and in poor weather. In that case, the guidance is active radar. In passive radar guidance, the missile emits nothing at all. It carries only a receiver that detects radar signals coming from the target itself, such as ground based air defence radars or a warship’s radar, and homes in on them.
If the seeker is thermal, using infrared guidance, it works through sensors placed in the front of the missile that track the target based on its heat signature. Any object powered by an engine or producing thermal energy emits infrared radiation. Advanced sensors can detect that radiation and convert it into a thermal image of the target.
That is why this technology has long been used in air to air missiles and anti aircraft missiles that track aircraft engine heat.
In recent years, the same concept has begun to be used in some short range ballistic missiles, especially those designed to strike moving targets such as ships. As the warhead approaches the target zone, the thermal seeker scans the area for the vessel’s heat signature, such as its engine heat. Once the sensor identifies that heat source, the guidance system adjusts the warhead’s path to strike directly.
One commonly cited example is the Iranian Khalij فارس anti ship missile, which is believed to use an infrared or electro optical seeker in its terminal phase. This allows it to track a moving ship and strike it accurately from distances that may reach hundreds of kilometres. It is believed to have entered service in 2014 and is one of the earliest Iranian ballistic missiles designed specifically for anti ship use.
The main advantage of these seekers is that they allow the missile to actually see the target, rather than relying only on pre-set coordinates. This increases accuracy, particularly against high value or moving targets.
Electro optical seekers use a camera or imaging sensor to capture a picture of what lies ahead, compare it with the intended target profile, and then adjust the missile’s path until it strikes more accurately. These seekers can operate through normal imaging or infrared thermal imaging, which is why they are sometimes described as optical or thermal seekers.
This type appeared in Iran with the Qassem Basir missile, which Tehran unveiled in May 2025. According to what the Associated Press cited from Iranian state television, the missile can hit a designated target from at least 1,200 kilometres away, with improved guidance and manoeuvrability that help it evade defences. The footage released of the missile suggested the presence of an optical or thermal seeker in the terminal phase.
This triple combination of inertial guidance, satellite correction, and seekers has significantly improved the accuracy of some Iranian missiles.
For example, during Iran’s missile strike on Ain al Assad base in Iraq in January 2020, Iranian missiles, likely including Qiam and Zulfiqar, succeeded in hitting several point targets inside the base with precision. Satellite imagery showed that each missile came very close to its intended target.
A detailed analysis based on satellite images and missile remnants near the base found that some of the missiles used were originally upgraded derivatives of the Scud family, yet had become far more accurate than old Soviet versions. They were estimated to achieve accuracy between 10 and 100 metres at a range of around 700 kilometres.
Smart Guidance in the Fattah Missile
Perhaps the most significant recent achievement is the official introduction of the hypersonic Fattah missile, described as a hypersonic ballistic missile. Fattah 1 was unveiled in 2023, followed by Fattah 2 in late 2024.
The importance of this missile lies in its high speed, exceeding Mach 5, meaning more than five times the speed of sound, reaching around 6,170 kilometres per hour. The warhead itself may travel at roughly double that speed.
Fattah is a medium range ballistic missile with a range of around 1,400 to 1,500 kilometres and two stages. The first uses solid fuel to propel the missile into near space. The second is a gliding stage that carries the warhead and manoeuvres with a specific aerodynamic design.
The hypersonic warhead can change course in the upper atmosphere at very high speeds, making its trajectory highly unpredictable to radar and complicating interception by defence missiles. Available information suggests that Fattah is equipped with an inertial navigation system integrated with satellite guidance reception to update its position and achieve maximum possible accuracy during the glide phase.
As it approaches the target, the missile is likely to rely on trajectory shaping software rather than a traditional radar, thermal, or optical seeker. This is due to the technical difficulty of fitting a seeker capable of functioning under the extreme heat generated by hypersonic speeds.
Still, it is not impossible that Iran has experimented with advanced radar or thermal seekers able to survive such conditions.
Trajectory shaping software refers to algorithms inside the missile’s guidance system that do not merely bring it to the target, but determine how it gets there. Instead of taking the shortest and most direct path, these algorithms can make the missile approach from a certain angle, fly at an altitude or on a path that is less predictable, manoeuvre at specific moments, delay or accelerate phases of flight, or distribute energy and speed in ways that improve accuracy and make interception more difficult.
Put simply, this is not just a mind that knows where the target is. It is a mind that organises the shape of the journey itself. It can be compared to a driver who does not merely want to reach an address, but wants to choose the best route, avoid congestion and obstacles, and arrive from the most suitable direction.
Iran continues to promote Fattah as a missile capable of striking with very high precision. A report by the Missile Defense Advocacy Alliance, a research centre based in Virginia, estimated its theoretical accuracy at between 10 and 25 metres, placing it among the most precise tactical missiles in the world.
Outmanoeuvring Ground Defences
It is important to note that missile guidance is not only about hitting the target, but also about avoiding obstacles and threats during flight. A guided missile can manoeuvre and correct its path if the enemy attempts to jam or intercept it.
This feature is of major military importance because it increases the chances of overcoming an adversary’s air defences. For much of the Cold War, air and missile defence systems were designed on the assumption that ballistic missiles would follow relatively fixed ballistic paths after their boost phase ended.
Once radar detected a missile, military computers could rapidly calculate its likely path and determine a suitable interception point. This was the basis for systems like the American Patriot and the Israeli Arrow, which were designed to intercept missiles along their expected trajectories before they reached their targets.
These systems depend on accurate prediction of the missile’s path once detected early.
But that equation began to change with the emergence of advanced guidance systems and manoeuvrable warheads. Instead of falling along a near fixed line, modern missiles can make corrections in the terminal phase, altering the angle of descent or direction during atmospheric reentry. These manoeuvres may be relatively limited, but they are enough to create a slight deviation from the expected path, which can confuse an interceptor that relies on predicting a collision point in advance.
In the case of more recent Iranian missiles, their improved guidance makes impact points less predictable than those of traditional ballistic missiles. The problem becomes even more difficult with hypersonic systems that combine speed, manoeuvrability, and unusual flight altitudes.
Reports by the US Congressional Research Service indicate that the combination of speed, manoeuvrability, and non-traditional altitudes makes such missiles harder to detect and intercept than conventional ballistic missiles.
Alongside manoeuvre, some modern missiles use additional tactics to complicate air defence tasks. These include deploying decoys or small metallic fragments to mislead radar, or separating the warhead from the missile body at an early stage so that defenders struggle to determine which object is the real threat. A missile can also be programmed to execute sudden course deviations or sharp altitude changes as an interceptor approaches.
Saturation as a Weapon
In some attacks, Iran does not bet on one missile or one target, but on the density of fire itself. It may launch dozens, and sometimes hundreds, of missiles and drones within a short interval. This is a military method known as saturation.
The goal is to exhaust air defence systems. No matter how advanced these systems are, they remain limited in the number and type of targets they can detect, track, and intercept at the same time. When incoming threats arrive in large numbers and from simultaneous directions, the probability increases that some will get through. This does not necessarily mean that each missile is individually superior. Rather, the sheer number of targets becomes a weapon in itself.
This does not mean missiles cannot be intercepted, or that Iranian missiles are somehow exceptional in absolute terms. But developments in guidance and manoeuvrability have made interception more complex and more expensive.
For example, a widely circulated video during the current war, though not independently verified, appears to show an Iranian missile passing through more than ten Israeli interceptor missiles before striking its target. The footage shows the missile continuing its path despite repeated interceptor launches from Israeli air defence systems.
Whether the video is fully authentic or not, it reflects an important point of vulnerability in Israel’s multi layered missile defence network. Even when a large number of interceptors are launched, no system can guarantee a 100 percent interception rate.
This pattern of attack imposes a costly equation on the defending side. Every Iranian missile may force air defences to launch several expensive interceptors, rapidly consuming defensive stockpiles and increasing pressure on Israel.
At the same time, strikes against Iranian missile depots and launch platforms continue to intensify, gradually reducing the number of missiles Iran can launch each day.
From this angle, the war increasingly resembles a contest of stockpiles more than a simple exchange of fire. On one side stands Iran’s ballistic inventory. On the other stand the interceptor stockpiles of Israeli air defence systems. Between them lies another parallel battle of equal importance: intelligence and surveillance, seeking to identify missile launch sites and missile units inside Iran and destroy them before they fire.
Whichever side runs out of stock first may lose the war, or be forced to sit at the negotiating table and accept an agreement under terms it was not prepared to accept at the outset.
