In 1996, then United States (US) Commander-in-Chief of Space Command Joseph W Ashy famously touted that:
[s]ome people don’t want to hear this, and it sure isn’t in vogue, but-absolutely—we’re going to fight in space. We’re going to fight from space and we’re going to fight into space.[1]
For decades, the drums of war in space have been beating in an ever-louder fashion, emboldened by like-minded military hawks and . Unfortunately, the shared global commons of outer space that for over six decades has provided humanity with immeasurable has in recent years been labelled by , and as a “war-fighting domain”.
This past week, a fundamental shift in policy seems to have taken place when the Biden Administration unilaterally declared and committed the United States to “not conduct destructive direct-ascent anti-satellite (ASAT) missile testing”. Accompanying that commitment, the White House also released a statement which underlined that “[”.
Ground-breaking and legally binding
Though ground-breaking, contrary to the assertion that “the United States is the first nation to make such a declaration”, unilateral declarations with regard to space weapons have been made before. In 1983, then “not to be the first to put into outer space any type of anti-satellite weapon” and issued a “moratorium on such launchings for the entire period during which other countries, including the United States, will refrain from stationing in outer space anti-satellite systems of any type”.[2] The .
Since 2014, the United Nations General Assembly has annually adopted a resolution on the “no first placement of weapons in space”, and the vast majority of the international community agrees with the need of “upholding […] a political commitment not to be the first to place weapons in outer space”.[3] To date, 30 States have made such political statements.[4]
What is unique about the declaration of Vice President Harris is the context surrounding the statement that suggests it is more than a political commitment. International law provides that “declarations publicly made and manifesting the will to be bound” may create legal obligations on the State.[5] It does not matter whether the commitment was expressed orally or in the form of a press statement,[6] for what matters is “whether the language employed in any given declaration does reveal a clear intention”.[7] Whether there is intention to be bound depends on who is making the statement on behalf of the State in question, and the context and circumstances in which the statement was made.[8]
The statement by was made in “clear and specific terms”[9] as follows:
The United States will continue to be a leader in order to establish, to advance, and demonstrate norms for the responsible and peaceful use of outer space. […] It is clear there is strong interest among our international partners to develop these norms. We must write the new rules of road. And we will lead by example. […] I am pleased to announce that as of today, the United States commits not to conduct destructive direct-ascent anti-satellite missile testing.[10]
Clearly the stated commitment not to conduct destructive direct-ascent ASAT missile testing was addressed to the international community as a whole.[11] To have legal effect, a unilateral declaration neither needs “to be addressed to a particular State, nor [is] acceptance by any other State required”.[12]
The “factual circumstances in which the unilateral act”,[13] in this case an oral statement of commitment, can be contextualised in recent efforts by the Biden Administration to “[defend] international norms and rules”.[14] Indeed, the unilateral declaration must be read in light of the ongoing multilateral exchanges , and the upcoming . It is too early to tell how other States will respond to the unilateral declaration, and whether other States will join the US in making such declarations.
Vice President Harris spoke in front of assembled military personnel, and on behalf of the United States. As the Deputy Head of State, she was clearly acting under her authority and within her functions. Though under international law “there is no doubt that every head of State is presumed to be able to act on behalf of the State in its international relations”,[15] it has been recognised that “in modern international relations other persons representing a State in specific fields may be authori[s]ed by that State to bind it by their statements in respect of matters falling within their purview”.[16] As the Chair of the US National Space Council, Vice President Harris’ statements on issues falling within her purview no doubt can bind the United States. Therefore, “having regard to intention and the circumstances” in which the statements were made, the statements “must be held to constitute an engagement of the State”.[17]
Importantly, a “unilateral declaration that has created legal obligations for the State making the declaration cannot be revoked arbitrarily”.[18] It is safe to assume that other States will take note of and even rely on such a declaration “being effective”.[19] As good faith,[20] “confidence and trust […] are so essential in the relations among States”,[21] the United States, no doubt an influential and major actor on the international as well as space arena, may not easily and arbitrarily revoke its commitment not to conduct direct-ascent ASAT tests.
Though the unilateral declaration by the US is welcome, the US has consistently voted against UN General Assembly resolutions on the prevention of an arms race and no first placement of weapon in space. It will be of interest to see whether after Vice President Harris’ statement there will be a shift in US policy and whether the US’ actions support its words.
Heightened Space Weaponisation Concerns
Vice President Harris’ unilateral declaration comes just months after the most recent ASAT test conducted by Russia in November 2021. By no means is Russia the only State to have conducted such tests, for have over the years felt the necessity to demonstrate their capabilities of destroying space objects from Earth. The consequences of the disruption or destruction of even one part of the overall space infrastructure that is so crucial to civilian and strategic communications, navigation and position cannot be fathomed.
Indeed, high on the agenda at the United Nations (UN) for decades is the concern of an arms race in outer space,[22] and the placement (and arguably use) of weapons in outer space that would pose a “grave danger for international peace and security”.[23]
As welcome and ground-breaking as the latest US commitment may be, there is only the commitment not to conduct direct-ascent ASAT missile testing. Nothing suggests that the US has also committed not to use of direct-ascent missiles, and arguably it may very well reserve the right to use such destructive and debris-creating means of warfare in the exercise of self-defence against an armed attack.[24] To “” to the 1996 quote above, the latest US commitment says nothing about the testing or use of weapons in space or weapons from space. Indeed, it does not even address weapons that are not direct-ascent ASAT weapons.
While the Outer Space Treaty prohibits the placements of nuclear and other weapons of mass destruction (WMDs) in orbit,[25] it is silent on the use of weapons other than WMDs. It is completely silent on other means and methods of disabling, disrupting or destroying space objects through, for instance, electromagnetic, cyber or other means.[26] The US has repeatedly voiced its opposition of the Russo-Sino proposal on the Treaty on the Prevention of Placement of Weapons in Outer Space (PPWT), which aims to prohibit the placement of any weapons in outer space and the resort to the threat or use of force against space objects.[27] Geopolitical tensions and rapidly developing technologies have .
Though military and strategic interests have been integral to the exploration and use of outer space, the International Committee of the Red Cross (ICRC) has unequivocally stated that as with any new means or methods of warfare, “the weaponization of outer space is not inevitable but is a choice” that would increase the probability of armed conflict in outer space.[28] The spectre of the outbreak of an armed conflict in space cannot be fathomed, and the “absence of conflicts in space in the past could not be regarded as a guarantee of peace”.[29]
Greater clarity on the law needed
Just as the weaponisation of outer space is not inevitable, it is encouraging to note the White House statement that “[c]onflict or confrontation in outer space is not inevitable”.
In line with this assertion, and , since 2016, an International Group of Experts have been working on the ۲ݮƵ Manual on International Law Applicable to Military Uses of Outer Space (۲ݮƵ Manual). Scheduled for completion in the second half of 2022, the ۲ݮƵ Manual will be the world’s first manual clarifying the international law applicable to military uses of outer space during peacetime.
Even in the absence of definitive binding treaty rules or unilateral declarations with regard to the testing or use of weapons in space, weapons from space, or even weapons targeted toward space, there is a solid body of international law and international space law that guides and constrains State behaviour.
Space is a global commons that must be explored and used “for the benefit and in the interests of all countries”[30] and in accordance with international law, including the Charter of the United Nations.[31] States must always have due regard to the interests of other State when conducting space activities,[32] which means refraining from actions that would unjustifiably interfere with the rights of other States.[33]
Before undertaking any space activity which is expected to cause harmful interference with the space activities of other States, a State must seek consultation with those latter States[34]--an obligation that has been clarified as entering into consultations in good faith and taking into account the legitimate interests of other States.[35] All these obligations and conditions that attach to the freedom of exploration and use of outer space apply regardless of whether such activities are military or non-military in nature,[36] and regardless of whether such activities are performed by governmental or non-governmental entities.[37]
Such fundamental legal principles would place serious constraints on the testing and use of direct-ascent weapons, the spoofing and jamming of radiofrequency signals, unwanted rendezvous and proximity operations with space objects of an adversary, or the variety of means and methods aimed at disabling, disrupting or destroying of space objects of other States. The ۲ݮƵ Manual contains over 50 rules outlining the legality and illegality of various military and strategic uses and applications of outer space. By clarifying the limitations international law places on the threat or use of force in outer space, it is hoped the ۲ݮƵ Manual will further the belief that conflict in space is not inevitable.
With the unilateral declaration by the United States, accompanied by the commitment “to ensure outer space remains free from conflict”, there is great momentum to prevent the spread of conflict, and all the ensuing humanitarian tragedies and economic fallout therefrom, from extending into outer space.
Now more than ever is there a need for the clarification of the law. States, space stakeholders and the future ۲ݮƵ need more than just “common understandings of what is right, what is wrong, and what is acceptable” in outer space.[38] A conflict-free space environment governed by an international rules-based regime is in the interests of all States.
In this interconnected world where all States and stakeholders have become so reliant on space, we must distance ourselves from the nihilism of the inevitability of conflict and war, and reaffirm the commitment to explore and use in a safe, responsible and sustainable manner.
[1] “USSC Prepares for Future Combat Missions in Space”, Aviation week & space technology (5 August 1996) at 51 [emphasis in original].
[2] See also UNGA, Report of the Conference on Disarmament, UN Doc A/44/27 (1989) at 276.
[3] UNGA, No first placement of weapons in outer space, UN Doc A/RES/76/23(2021), para 5.
[4] Ibid, Preamble, para 11.
[5] Nuclear Tests (Australia v. France; New Zealand v. France), [1974] ICJ Rep 457, para 46. See also ILC, Guiding Principles applicable to Unilateral Declarations of States, UN doc A/61/10 (2006) at 367 et seq, Principle 1.
[6] Nuclear Tests, supra note 5, para 49.
[7] Temple of Preah Vihear (Cambodia v. Thailand), [1961] ICJ Rep 17 at 32. See also Guiding Principles applicable to Unilateral Declarations of States, supra note 5, Principle 5.
[8] Guiding Principles applicable to Unilateral Declarations of States, supra note 5, Principle 7.
[9] Armed Activities on the Territory of the Congo (New Application: 2002) (Democratic Republic of the Congo v. Rwanda), [2006] ICJ Rep 6, para 49. See also Guiding Principles applicable to Unilateral Declarations of States, supra note 5, Principle 7.
[10] “Remarks by Vice President Harris on the Ongoing Work to Establish Norms in Space” (18 April 2022), online: White House <>
[11] Nuclear Tests, supra note 5, para 53. See also Guiding Principles applicable to Unilateral Declarations of States, supra note 5, Principle 6.
[12] Nuclear Tests, supra note 5, para 52.
[13] Frontier Dispute (Burkina Faso v. Republic of Mali), [1986] ICJ Rep 554, para 40.
[14] “Remarks by Vice President Harris on the Ongoing Work to Establish Norms in Space”, supra note 10.
[15] Application of the Convention on the Prevention and Punishment of the Crime of Genocide (Bosnia and Herzegovina v Yugoslavia) [1996] ICJ Rep 595, para 44. See also Land and Maritime Boundary between Cameroon and Nigeria (Cameroon and Equatorial Guinea (intervening) v Nigeria), [2002] ICJ Rep 303, para 265.
[16] Armed Activities on the Territory of the Congo (New Application: 2002), supra note 9, para 47.
[17] Nuclear Tests, supra note 5, para 51; and Armed Activities on the Territory of the Congo (New Application: 2002), supra note 9, para 46. See also Guiding Principles applicable to Unilateral Declarations of States, supra note 5, Principle 4.
[18] Nuclear Tests, supra note 5, para 53. See also Guiding Principles applicable to Unilateral Declarations of States, supra note 5, Principle 10.
[19] Nuclear Tests, supra note 5, para 53.
[20] Nuclear Tests, supra note 5, para 46. See also Declaration on Principles of International Law Concerning Friendly Relations and Co-operation Among States, GA Res 2625 (XXV), UN GAOR, 25th Sess, Supp No 22, UN Doc A/2212 (1970).
[21] Nuclear Tests, supra note 5, para 53
[22] UNGA, Prevention of an arms race in outer space: report of the 1st Committee, UN Doc A/75/397 (2020); and UNGA, Prevention of an arms race in outer space, UN Doc A/RES/76/22 (2021).
[23] UNGA, Practical Measures for the Prevention of an Arms Race in Outer Space, UN Doc A/RES/76/230 (2021), Preamble, para 2-3.
[24] US, Department of Defense, Law of War Manual, June 2015 (updated December 2016), 14.10.4 [“[…] lawful military activities in self-defense (e.g., missile early warning, use of weapon systems) would be consistent with the use of space for peaceful purposes, but aggressive activities that violate the Charter of the United Nations would not be permissible”].
[25] Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies, 27 January 1967, 610 UNTS 205 (entered into force on 10 October 1967), art IV [Outer Space Treaty].
[26] See UNGA, Group of Governmental Experts on further practical measures for the prevention of an arms race in outer space, UN Doc A/74/77 (2019), para 36.
[27] Treaty on Prevention of the Placement of Weapons in Outer Space and of the Threat or Use of Force against Outer Space Objects, art II, online: Reaching Critical Will <reachingcriticalwill.org/images/documents/Disarmament-fora/cd/2014/documents/PPWT2014.pdf>
[28] ICRC, Position paper submitted by the International Committee of the Red Cross to the Secretary-General of the United Nations on the issues outlined in General Assembly Resolution 75/36, 8 April 2021, online: <.
[29] UNCOPUOS, Report of the Committee on the Peaceful Uses of Outer Space, UN Doc A/74/20 (2019), para 54.
[30] Outer Space Treaty, supra note 25, art I.
[31] Ibid, art III.
[32] Ibid, art IX.
[33] Chagos Marine Protected Area Arbitration (Mauritius v. United Kingdom), Award of 18 March 2015, PCA No 2011-03 (2015), paras 471, 540.
[34] Outer Space Treaty, supra note 25, art IX.
[35] UNGA, Report of the International Law Commission on the work of its fifty-third session, 23 April -1 June and 2 July - 10 August 2001, Official Records of the General Assembly, Fifty-sixth session, Supplement No.10, UN Doc A/56/10 (2001), “Prevention of Transboundary Harm from Hazardous Activities with Commentaries” at 148 et seq at 160. See also Lac Lanoux (Spain v. France), (1957) XII RIAA 281, para 17.
[36] UNGA, First Committee, 1289th Meeting, UN Doc A/C.1/PV.1289 (1962) [“It is the view of the United States that outer space should be used only for peaceful-that is, non-aggressive and beneficial-purposes. […] Until this is achieved, the test of any space activities 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”].
[37] Outer Space Treaty, supra note 25, art VI.
[38] “Remarks by Vice President Harris on the Ongoing Work to Establish Norms in Space, supra note 10.