Hundreds of miles above the earth, thousands of satellites are enabling the battle for Ukraine. Elon Musk’s Starlink satellites provide the connectivity to Ukraine’s armed forces that is vital for targeted drone strikes against Russian units. Meanwhile, commercial imaging satellites deliver crucial battlefield intelligence to Ukrainian soldiers. It is therefore unsurprising that the conflict in Ukraine has been dubbed the first commercial space war. Defence analysts frequently point to the Gulf War (1990-91) as the first space war due to the integration of satellites into the US-led coalition’s combat operations. However, neither of these claims about the role of satellites in conflict is wholly accurate. American forces first used satellites during the Vietnam War and commercial communications satellites played an important role during the First Gulf War. These historical nuances aside, satellites, particularly commercial ones, have become woven into the fabric of modern warfare, intensifying military competition in space.

The very idea of space conflict conjures up images of space battleships that could be taken from the pages of a Jules Verne novel. The US military’s newest service, the Space Force, has already been incorporated into kitschy popular culture representations of space conflict. But space systems constitute a multi-billion-dollar information infrastructure for the United States to project power across the globe. Russia and China have also heavily invested in weapons designed to degrade and destroy the satellites that are so crucial for the US way of warfare.

Although it is only recently that the United States has labelled space as a ‘warfighting domain’, it was during the Cold War that the Pentagon first prepared for combat actions in space. By the 1970s, satellites were increasingly vital for global connectivity and rapidly targeting enemy forces. These technological developments ultimately allowed the United States to achieve more flexible nuclear and conventional strike options. At this same time, both the United States and the Soviet Union were developing weapons designed to attack satellites used for military support. Together, these events constitute the largely secret (until recently) genealogy of military competition in space, explored in my recent book Weapons in Space: Technology, Politics, and the Rise and Fall of the Strategic Defence Initiative.

Detailing this history is crucial for understanding how and why space has once again emerged as a domain of great power contestation. There are important differences between the Cold War and today, however. In particular, the proliferation of systems designed to attack satellites as well as the emergence of the commercial space arena have dramatically increased the scale of military competition in space. From a technological perspective, the US shift towards satellite constellations consisting of hundreds, and in some cases, thousands of satellites – called proliferated constellations – represents one of the most significant developments since the beginning of the space age. With these larger networks, the United States – and its allies by extension – is achieving far greater resilience. But the threats are not dissipating. As shown in Ukraine, electronic and cyber-attacks against space systems have become part and parcel of modern warfare.

During the Cold War, the United States had three space programmes. The first, and most visible, was NASA’s civil space endeavours focused on scientific and exploration projects. The second was the Pentagon’s military space programme, which included communications, weather, navigation, and early warning satellites. The third was the intelligence space programme overseen by NASA’s secret sibling, the National Reconnaissance Office (NRO). This clandestine agency was responsible for the development and operation of reconnaissance satellites designed to peek behind the Iron Curtain. By the early 1960s, satellite reconnaissance was the single largest source of intelligence on Soviet military power.

The Eisenhower administration publicly committed the United States to using space for peaceful purposes, which did not preclude national security activities such as communications and reconnaissance. Eisenhower did, however, constrain the aspirations of some senior military leaders, predominantly from the air force, to build offensive spacecraft that could be used to strike Soviet targets. Such capabilities were of limited military utility at the time. More importantly, they would have undermined the president’s objective of creating an international political framework that legitimised reconnaissance from space. Fundamentally, for the United States, the most important aspect of US national security space projects was carrying out reconnaissance to monitor the Soviet Union and China. The president did not want to take any actions that could provoke the Soviet Union into interfering with US space systems.

Despite its commitment to the peaceful uses of space, the United States did carry out multiple tests of nuclear-tipped anti-satellite weapons in the late 1950s and 1960s. But American officials quickly learned that propagating radiation into space would indiscriminately damage satellites, including its own. One such high-altitude nuclear test, called ‘Starfish Prime’, damaged approximately one third of all satellites in orbit at that time.

Aside from the fact that nuclear anti-satellite weapons were incapable of precision targeting, there was little incentive in the 1960s to field anti-satellite capabilities because reconnaissance satellites did not yet play a direct military role. At this time, spaceborne reconnaissance systems had to use film-return capsules to deliver imagery to analysts on the ground – a process that involved aircraft capturing the capsules in midair and then flying them to Eastman Kodak for processing, which could take weeks. The satellites collected intelligence that provided invaluable insights into the Soviet order of battle and strategic weapons development, but they could not yet be used for time-sensitive monitoring and targeting of adversary forces.

American fears about Soviet orbital nuclear weapons did, however, prompt the United States to field a land-based nuclear anti-satellite weapon. In the early 1960s, some senior US officials concluded that the Kremlin might deploy orbital nuclear weapons. In response, the Pentagon deployed an anti-satellite weapon called Programme 437, located on Johnston Island in the Pacific that became operational in 1964. The system was designed to destroy incoming nuclear warheads with its nuclear weapons.

With the signing of the 1967 Outer Space Treaty that prohibited weapons of mass destruction in space, US anxieties about Soviet orbital weapons cooled. The Kremlin did indeed field a Fractional Orbital Bombardment System that consisted of nuclear weapons designed to evade US missile defence radars by flying on a southerly trajectory in orbit before releasing their warheads and impacting their targets. However, US defence experts recognised that these weapons were not particularly accurate.

By the early 1970s, the majority of US national security space activities consisted of placing sensors in space for reconnaissance and early warning of nuclear attacks, communications satellites for transmitting command and control messages, satellites for monitoring weather, and satellites for navigation. The Soviet Union had deployed reconnaissance and communications satellites, though it was less dependent on space systems than the United Sates. Fundamentally, in this period both the United States and the Soviet Union were deploying information infrastructures in space for collecting and transmitting data, rather than focusing heavily on fielding weapons for attacking space-based and terrestrial targets.

The first combat test for US space technologies occurred during the Vietnam War. Nascent communications satellites were used to relay messages between the United States and forces in South Vietnam since high-frequency radio was unreliable and submarine cable connections were inadequate. Communications satellites also transmitted intelligence between combat forces in Vietnam and intelligence analysts in Washington. In addition, for the first time the NRO carried out tests for disseminating space-based intelligence to tactical Air Force and naval units that was used for battlespace awareness and targeting. This was the first instance of space systems being harnessed for tactical military applications, albeit in a very limited form.

Beginning in the late 1960s the Soviets launched radar satellites that were designed to track naval vessels. In the mid-1970s, these systems were complemented by satellites that could locate ships based on their signal emissions. These developments revealed that the Soviets were using satellites to carry out ocean surveillance and provide targeting data to weapons systems, thereby creating a threat to the survivability of NATO vessels in wartime.

In tandem with these satellites, the Soviet Union fielded a non-nuclear anti-satellite weapon designed to attack American satellites. Unlike the Soviet Union, which launched large numbers of reconnaissance spacecraft, the United States developed fewer systems. Amrom Katz, a technical expert at the RAND Corporation, decried the situation, warning that American satellites were ‘juicy’ targets for Soviet anti-satellite weapons. He feared that in the lead up to a conflict, the Soviet Union might use anti-satellite weapons to poke out America’s eyes and ears in space. Notably, however, the Soviet Union’s anti-satellite weapon could not reach the higher orbits where US nuclear command and control satellites were located.

In response to the Soviet anti-satellite programme, President Gerald Ford directed a review, led by physicist Solomon Buchsbaum, of US national security space policy. Buchsbaum’s study concluded that a US anti-satellite weapon would not deter Soviet officials from using theirs in wartime, but argued that the United States needed the ability to attack Soviet military-support satellites. The report stressed that it was against the US national interest to treat space as a ‘sanctuary’, and predicted that as space systems became more pervasive in military operations, they would naturally become targets.

The emergence of sophisticated electronics in the 1970s permitted the United States to develop anti-satellite weapons that could more precisely target Soviet space systems – these were believed to be far more effective than nuclear anti-satellite weapons. In Ford’s final days in office he directed the Pentagon to develop an air-launched anti-satellite weapon and an electronic warfare capability for jamming Soviet satellite command links. While these developments did not amount to a declaration of space as a ‘warfighting domain’ – this would not occur until 2017 – they did represent a shift towards a more militarily competitive approach to space.

Shortly after entering the White House in 1981, President Ronald Reagan pushed forward with a US anti-satellite weapon, called the Miniature Homing Vehicle, in 1985. This system would carry out only one destructive test before its cancellation that year. Most controversially, Reagan initiated the Strategic Defence Initiative to develop land- and space-based missile defences. Due to its commitment to fielding space-based missile defence, the United States avoided any limits on military space capabilities during the superpower arms control negotiations in the second half of the 1980s and early 1990s. Consequently, unprecedented nuclear arms control agreements were not accompanied by any binding constraints on the military uses of space.

The standard narrative concerning the Strategic Defence Initiative treats the programme as a technological failure without considering its enduring consequences for the military uses of space. Long before SpaceX and Starlink, engineers working on the Strategic Defence Initiative envisioned the development of proliferated constellations of hundreds or even thousands of satellites. Such a large number of satellites were believed to be much more resilient against Soviet anti-satellite weapons than a few highly sophisticated space systems. While this concept would not come to fruition in the 1980s or early 1990s, the Pentagon is today fielding the Proliferated Warfighter Space Architecture, which consists of many satellites in low earth orbit designed to track advanced missile threats through all phases of flight.

By the end of the Cold War, satellites were critical components of the American global war machine. Reconnaissance satellites were vital for near-real-time targeting of enemy forces and played a central role in the US shift towards more flexible nuclear and conventional targeting postures. The arrival of GPS – a programme which some air force officials had tried to eliminate in the 1970s – allowed US military forces to carry out precision strikes against enemy targets. GPS delivered all-weather positioning, navigation, and timing. A new generation of nuclear-hardened communications satellites provided the United States, and its allies, assured connectivity for this function on a global scale.

All of these space technologies were designed to ensure that NATO would prevail in a conflict with the Warsaw Pact, but they were first put to the combat test in the Kuwaiti desert in 1990-91. Although most munitions dropped during the First Gulf War were ‘dumb bombs’, GPS-guided munitions proved very effective, and GPS was also vital for assisting US combat forces in moving through the desert sands of the Persian Gulf.

Defence Support Programme satellites delivered warnings of Iraqi Scud attacks, underscoring that strategic systems had immense tactical value. Defence Support Programme satellites also aided US military forces in finding and destroying Scud launchers. Satellite communications provided 90 per cent of the connectivity for US and coalition forces, and nearly a quarter of this bandwidth was supplied by commercial satellite communications.

Reconnaissance satellites also aided US and allied combat forces – though this history cannot yet be fully told because many of the archival materials remain classified. Nevertheless, a declassified NRO history observes that ‘imagery and signals intelligence [satellite] systems played an important role in the decisive US-led victory’. But NRO historian Bruce Berkowitz also points out that the war revealed how NRO satellites ‘were often ill-suited to support combat operations’.

Unlike intelligence assets controlled by combatant commanders, the military services could not directly task these satellites. All of this suggests that while space technologies played a critical role during the conflict, there was still much work to do in integrating satellites into tactical combat operations.

Even though no satellites were physically attacked during the conflict, the Gulf War reinvigorated debates about offensive space weapons. Senior defence planners pointed out that if Saddam had possessed counter-space weapons, it would have been much more difficult for the United States to so effectively harness space technologies for combat. Air force Chief of Staff Merrill McPeak stressed the importance of satellites for modern warfare – designating the Gulf War the ‘first space war’ – but he stopped short of pushing for any new offensive space systems. Instead, the Pentagon prioritised development of capabilities, such as jammers, that produce reversible effects.

At this time, there was no immediate threat to US superiority in space, but some American officials worried that this situation would not continue. In January 2001, the US Commission to Assess United Stations National Security Space Management and Organization produced a report that warned about the possibility of a ‘space Pearl Harbor’. Its authors called for more investment in resilience measures as well as fostering the growth of commercial space systems. But after the attacks on 11 September 2001, US government priorities were elsewhere.

China’s 2007 demonstration of an anti-satellite weapons capability forced US officials to more closely consider the security of their satellites. That year, Beijing destroyed one of its own satellites in low earth orbit, producing significant debris in the process. Only one year later, the US Navy used an SM-3 missile defence interceptor to eviscerate a malfunctioning US satellite in an operation called ‘Burnt Frost’. While this was not officially an anti-satellite weapons test, observers in Beijing and Moscow interpreted it as such. Burnt Frost underscored that advanced missile defence interceptors possessed latent anti-satellite weapons capability. Thus, even if the United States did not have dedicated counter-space weapons, it reminded the world that it possessed the technological means to attack satellites.

Beijing’s anti-satellite weapons test highlighted a critical US vulnerability, but it did not result in any significant and immediate changes. American officials were still consumed with wars in Iraq and Afghanistan. But as US anxieties about potential conflict with China intensified in the following decade, space security could not be ignored. Moreover, the space environment was rapidly changing. A commercial space industry was fast emerging and the number of government actors in space was quickly expanding. In addition to China, Russia also reinvigorated its counter-space programmes. In the words of the Obama administration, space was becoming congested, contested, and competitive.

President Donald Trump’s creation of the Space Force seemed to illustrate the realisation that changes were needed to address the growing sophistication of threats to US national security satellites. The new service came in the wake of the reestablishment of US Space Command, a combatant command with responsibilities for the space domain. Since the Space Force was the first new American military service since the creation of the air force in 1947, growing pains were to be expected. Indeed, senior defence officials overwhelmingly opposed the new service. Notably, the Space Force did not take over all national security space capabilities. The National Reconnaissance Office and the Missile Defence Agency both remain independent entities despite their significant national security space equities.

Bureaucratic changes aside, marked transformations are underway in how countries are integrating space capabilities into combat operations. For the first time since the beginning of the space age, the United States is shifting away from a space acquisition model that prioritises the development of only fewer systems that are highly capable. Instead, the Department of Defense and the intelligence community are fielding proliferated constellations of hundreds of satellites. More satellites in orbit renders traditional anti-satellite weapons less effective because there are far too many targets.

Proliferated satellite constellations are not, however, immune from vulnerabilities. A nuclear detonation in space would destroy large numbers of satellites in orbit, which might explain US reports about a potential Russian nuclear anti-satellite weapon. While this might seem like a dystopian doomsday weapon, it could reflect anxiety in the Kremlin about Ukraine’s effective use of Elon Musk’s Starlink satellites. These communications satellites, which are part of the proliferated constellations, have proved very resilient against Russia’s electronic warfare attacks. Nevertheless, the ground systems that control satellites are suspectable to cyber-attacks that could degrade or even deny the use of satellites.

Starlink is emblematic of the dramatic expansion of commercial communications satellites and imaging satellites that have profound consequences for modern warfare. Countries such as Ukraine can harness these space systems without acquiring their own. Moreover, the US government is purchasing commercial satellite services because they enhance the survivability of its own space systems. But these commercial satellites are also attractive targets, since they enable combat actions. This situation is not unprecedented. Since the 19th century, governments have used commercial submarine cables and radio to transmit vital national security data, thereby rendering commercial telecommunications infrastructure targets in wartime. Commercial satellites are no different.

Pointing to the importance of space systems for warfighting, Secretary of the US Air Force Frank Kendall recently observed that ‘space isn’t just a warfighting domain, it is the warfighting domain’. Similarly, General Chance Saltzman, the head of the US Space Force, has described space as more contested than at any other time in history. Certainly, the war in Ukraine has proven that space technologies can play a game-changing role in conflict. But the recent attention devoted to space security should not overshadow its long history. Rather than a new international security issue, the role of space in military affairs is returning to centre stage after a three-decade hiatus.

Recent developments represent a return to the intensifying great power competition in the cosmos towards the end of the Cold War, although today there are important differences. It would be imprudent to characterise the current situation in space as Cold War 2.0. The number of space actors, both government and commercial, stands in stark contrast to the Cold War period. The fact that Ukraine can harness commercial space systems to produce lethal results on the battlefield is emblematic of how far space power has evolved since the United States first employed satellites in combat operations during the Vietnam War. Notably, Russia’s targeting of commercial space systems has been largely ineffective, but analysts should be careful about drawing too many conclusions about what Ukraine might mean for a war involving direct combat between sophisticated space and counter-space actors, such as the United States and China. Space conflict has begun, and it is here to stay.