The “Peaceful Use” of Outer Space?


Would the United States unilaterally offer its greatest rival the complete demilitarization of a valuable military domain? This may sound impossible, but at the beginning of the space age, such an offer was no science fiction fantasy or globalist pipe dream. On Oct. 10, 1957 — less than a week after the Soviet Union’s Sputnik-1 became the first human-made object launched into outer space — Henry Cabot Lodge, the Eisenhower administration’s representative to the United Nations, made just such a proposal to the U.N.’s political and security committee. In his speech, Lodge made an impassioned plea that the outer space environment be used exclusively for peaceful purposes. The United States, Lodge said, sought the creation of an international inspection system to assure that all space launches took place “for exclusively peaceful and scientific purposes.” Most surprising of all, America’s desire to see the complete demilitarization of space was so strong that it was “prepared to join [such an] initiative without awaiting the conclusion of negotiations on … other substantive proposals” (emphasis added). In other words, ongoing negotiations involving arms control, nuclear restraint, and other international political obstacles between the United States and Soviet Union would play no role in America’s willingness to demilitarize space. The Soviet Union, unsurprisingly, rejected Lodge’s overture. His speech, however, stands as an astonishing vision of what outer space might have been.

Nearly 65 years after Lodge’s proposal, the idea that the United States would seek to voluntarily limit itself to “exclusively peaceful” uses of outer space seems completely far-fetched. America has employed space-based force-support technologies since before the first Gulf War, recognized outer space as a “warfighting domain,” and, in 2019, created the Space Force, a new military branch specifically devoted to outer space military and support operations. And yet, questions and tensions concerning the use of space for peaceful purposes persist. “Peaceful” use of outer space is frequently cited at the international level as a goal, if not an unwritten requirement, of space activities. Such language is also widely employed in U.S. space policy documents, including presidential national space policies. Even the Space Force’s June 2020 doctrine document states that “[i]n keeping with international law, the United States acknowledges that the use of space is for peaceful purposes.”



But is there truly a requirement under international law that space be used solely for peaceful purposes? If so, to what extent does this requirement, or the American interpretation of this requirement, limit military operations in outer space? The answers to these questions may be surprising. There is no generalized international legal requirement that outer space be used solely for peaceful purposes, although there are explicit prohibitions on certain weapons and military activities in particular areas of space. Celestial bodies such as the moon, for instance, are subject to exclusively peaceful use requirements under existing international law. These restrictions, however, do not apply to interplanetary space — the areas between celestial bodies, including Earth orbit, cislunar space and cislunar orbit, and farther areas of deep space. Ultimately, existing international space law provides significant leeway for both the United States and its potential adversaries to engage in military space activities.

The first internationally binding legal instrument to focus exclusively on outer space legal issues, the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (better known as the “Outer Space Treaty”), entered into force in October 1967. This was almost exactly a decade after the Sputnik launch and the Eisenhower administration’s initial proposals concerning internationally monitored, exclusively peaceful uses of space. Between 1957 and 1967, the concept of what it meant to use outer space for peaceful purposes had undergone a seismic shift, particularly in the eyes of the U.S. government. While Lodge’s 1957 proposal appears to have been completely in earnest (other U.S. government officials publicly asserted similar policy goals at the time), the Eisenhower Administration quickly recognized that advocating “exclusively” peaceful uses of outer space could significantly limit America’s ability to harness space for critical national security purposes. Chief among these was the development and use of reconnaissance satellites, which would provide the United States with valuable intelligence on Soviet activities.

Thus, when the Eisenhower Administration created its official “U.S. Policy in Outer Space” in 1959, it began the process of reinterpreting America’s early advocacy for using outer space for exclusively peaceful purposes. Eisenhower’s policy acknowledged earlier U.S. proposals on the subject and articulated continued American support for the principle that outer space should be free and available for peaceful exploration and use by all states. However, the policy also mandated the completion of “a study of the implications for the national security of the expression ‘peaceful uses of outer space’ with a view to defining this expression in a manner that would best serve the interests of the [United States].” (emphasis added). The policy is also careful to note that peaceful use of space “does not necessarily exclude military applications.” In short, the Eisenhower Administration began artfully backtracking on its initial, post-Sputnik proposals for “exclusively peaceful” use of space.

In conjunction with the development of national space law and policy, both the Eisenhower and Kennedy Administrations were instrumental in pressing for the development of space law at the international level. America’s Eisenhower-era push to create an international forum for outer space issues successfully resulted in the creation of first an ad hoc, and then a permanent, United Nations Committee on the Peaceful Uses of Outer Space. This committee is, among other things, devoted to “study[ing] the nature of legal problems which may arise from the exploration of outer space.” Among the committee’s early successes was the creation of a non-binding Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space. The declaration contains a number of critical space law principles that would become binding parts of the Outer Space Treaty, including that outer space and celestial bodies be free for exploration and use by all States; that outer space and celestial bodies are not subject to national appropriation; and that States launching objects into outer space shall be internationally liable for the damage those objects may cause. It does not, however, contain any requirement that outer space be used exclusively for peaceful purposes. The closest the Declaration of Legal Principles comes to discussing such an idea is in its preamble, which “[r]ecogniz[es] the common interest of all mankind in the progress of the exploration and use of outer space for peaceful purposes” and “[d]esir[es] to contribute to broad international co-operation . . . in the legal aspects of exploration and use of outer space for peaceful purposes.” These equivocal formulations do not impose even a non-binding principle of use for peaceful purposes.

By the time the Declaration of Legal Principles was working its way toward a vote by the General Assembly, America had largely solidified its reinterpretation of the use of outer space for peaceful purposes. A representative example of this shift can be found in December 1962, when Senator Albert Gore, Sr., addressed the United Nations First Committee on the subject of international cooperation in space and the work of the committee on the peaceful use of space. Citing the difficulty in distinguishing between military and non-military uses of outer space technologies, as well as the “dual-use” problems of technologies that could be employed for both military and non-military purposes, Senator Gore explained to the First Committee that

[i]t is the view of the United States that outer space should be used only for peaceful — that is, non-aggressive and beneficial — purposes. . . . . Until [general disarmament] is achieved, the test of any space activity must not be whether it is military or non-military, but whether or not it is consistent with the United Nations Charter and other obligations of law. [Emphasis Added]

Senator Gore’s comments are among the earliest public articulations of the American shift from the “exclusively” peaceful formulation of space-use from 1957 to the “non-aggressive” formulation that continues to govern U.S. actions in space to this day.

It was with this interpretation of peaceful uses of space that the United States entered into negotiations with the Soviet Union and the other nations of the UN committee to develop a binding space treaty during the mid-1960s. The resulting Outer Space Treaty continues to serve as the cornerstone of international outer space law. The treaty’s preamble repeats the equivocal, non-binding peaceful use language of the declaration mentioned above. Preambles are one of several essential tools used to interpret a treaty’s purposes, and, thus, the Outer Space Treaty’s preamble should not be disregarded as mere ornamentation to the treaty. That said, preambles do not impose binding legal obligations on states in the same way that substantive articles do. Thus, the “peaceful purposes” language of the Outer Space Treaty’s preamble is not a binding requirement, but merely an interpretive aid to the treaty’s substantive provisions.

Among those provisions are two articles that directly pertain to the use of outer space for peaceful purposes. First, Article III stipulates that outer space activities be undertaken “in accordance with international law, including the Charter of the United Nations.” The brevity of this article belies its significance. Effectively, Article III applies the full breadth of international law, including the laws of armed conflict and the UN Charter’s Article 2(4) prohibition on the threat or use of force, to state action in outer space. While the American position on peaceful purposes solidified before the drafting of the Outer Space Treaty, Article III’s application of international law on a galactic scale provides significant support for America’s “non-aggressive” interpretation. Second, whereas the Declaration of Legal Principles was largely silent on questions of military uses of space, the Outer Space Treaty addressed the subject directly, in Article IV:

States Parties to the Treaty undertake not to place in orbit around the earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction, install such weapons on celestial bodies, or station such weapons in outer space in any other manner.

The moon and other celestial bodies shall be used by all States Parties to the Treaty exclusively for peaceful purposes. The establishment of military bases, installations and fortifications, the testing of any type of weapons and the conduct of military manoeuvres on celestial bodies shall be forbidden.

In other words, while celestial bodies are to be used only for exclusively peaceful purposes, certain military uses of interplanetary space are, by omission, permitted! If only “nuclear weapons” and “weapons of mass destruction” are explicitly prohibited from being placed in orbit, a wide range of “conventional” weapons — and dual-use military/civilian space objects, such as satellites (including many varieties of military satellites) — are permitted. The distinction between celestial bodies and interplanetary space is critical when considering permissible military activities in outer space. The United Nations has attempted to create additional international law more restrictively interpreting use of outer space for peaceful purposes, such as the Moon Agreement, an international treaty that has received only minimal support. Other states, most notably Russia and China with their recent draft Treaty on the Prevention of the Placement of Weapons in Outer Space, have sought more expansive and explicit prohibitions on space weapons. To date, such efforts have come to naught. This leaves the provisions of the Outer Space Treaty as the primary, binding international law related to military and peaceful uses of outer space.

Even after ratifying the Outer Space Treaty, the United States continued, and continues, to recognize the principle of exploration and the use of space for peaceful purposes, while simultaneously using the non-aggressive formulation of peaceful purposes to define that term so broadly as to provide no meaningful constraint on U.S. space activity. This can be seen in the America’s national space policies, which have been issued by each presidential administration since the Carter administration. President Jimmy Carter’s 1978 national space policy, for instance, recognized the American “[c]ommitment to the principles of the exploration and use of outer space . . . for peaceful purposes,” but went on to state that peaceful purposes allow “military and intelligence-related activities in pursuit of national security and other goals.” Similar caveats to the peaceful purposes principle can be found in every subsequent space policy, including the three most recent, of the Bush, Obama, and Trump Administrations. President George W. Bush’s 2006 space policy defined peaceful purposes as allowing “U.S. defense and intelligence-related activities in pursuit of national interests;” President Barack Obama’s 2010 version stated that space could be legitimately used for “national and homeland security activities;” and President Donald Trump’s December 2020 space policy, which remains in effect, maintains that, “consistent with [the ‘peaceful purposes’] principle, the United States will continue to use space for national security activities, including for the exercise of the inherent right of self-defense.” Such vast inclusions under the peaceful purposes principle largely allow the United States a free hand in its space activities — apart from those activities and space weapons specifically prohibited by the Outer Space Treaty.

Use of outer space for national security purposes has been a priority for the United States since the Eisenhower administration. Recently, however, the U.S. political establishment has exhibited renewed interest in space security and military use issues. During the Trump administration, Space Command — the military combatant command in charge of conducting operations in, from, and to space — was resurrected in August 2019, after it had been decommissioned in 2002. In December 2019, after receiving congressional approval in the 2020 National Defense Authorization Act, the Space Force followed. While Trump’s interest in outer space and advocacy for the Space Force was much-maligned during his presidency, the Biden administration has, at least so far, indicated it intends to fully support both the Space Force and other Trump administration space initiatives. As noted at the beginning of this article, the Space Force has recognized the peaceful purposes principle as a key component of international space law, and the Space Command Commander’s Strategic Vision “champion[s] and promote[s] the responsible,  peaceful, and safe use of space” — while recognizing the country’s inherent right to self-defense.

As America’s international competitors, primarily Russia and China, increase their own military space activities, concerns regarding the use of space for peaceful purposes are likely to become even more pronounced. Over the past year alone, Russia has tested both space-based and direct-ascent anti-satellite weapons — activities the United States has decried as “irresponsible,” but which are not prohibited under existing international space law. China, which infamously destroyed one of its own satellites with a direct-ascent anti-satellite weapon in 2007, is also believed to be developing a wide range of anti-satellite and space weapons. The use of such weapons by China, Russia, or the United States would violate, or, at least, implicate, the Outer Space Treaty’s Article III application of other areas of international law, including the laws of armed conflict, to outer space. However, the Outer Space Treaty and international space law permit the development of such weapons and their placement into orbit, provided they do not constitute “weapons of mass destruction.”

International space law has come a long way from Henry Cabot Lodge’s initial advocacy of an internationally monitored system for exclusively peaceful uses of space. There is, however, still little in the form of binding space law to restrict military activities in Earth orbit and other areas of interplanetary space. For the United States, with its long-standing recognition, but expansive interpretation, of the use for peaceful purposes principle, this provides a solid legal basis for the activities of U.S. Space Command, the Space Force, and the other American military and intelligence organizations. Existing law, however, also enables and emboldens the military space efforts of American competitors. This has become especially significant as other States have recognized the significant military and force-support benefits of outer space technologies, resulting in the majority of space-faring states having come to agree with America’s “non-aggressive” interpretation of peaceful space use. As outer space use continues to expand, and as both American and international space-oriented military organizations vie for strategic superiority in orbit, interpretations of what it means to use outer space for peaceful purposes are likely to play an even more prominent role in state space activity.



Maj. Jeremy Grunert is an attorney in the U.S. Air Force Judge Advocate General’s Corps. He is currently assigned to the Air Force Academy, where he serves as an assistant professor in the department of law. He is the course director for the academy’s space law course. This article is written in Maj. Grunert’s personal capacity and does not necessarily reflect the official views of the U.S. government, the Department of Defense, or the Department of the Air Force.

Image: Space Force