Outer space is becoming an arena for technological shows of force – whether by deployment of spy satellites or testing of weapons. What does international space law have to say on the militarization of space? In this three-post series, Pavle Kilibarda attempts a broader interpretation of the norms, one that would lead to a more pacifist reading of the law. The triad supplements Intercross’ series Why Outer Space Matters, which came out of the October 2016 Inaugural Plenary of the MILAMOS Project in Montreal, Canada.

The fact that international space law’s bedrock document, the 1967 Outer Space Treaty, refers to outer space as the “province of all mankind” (Art. I), the exploration and use of which “for peaceful purposes” is the common interest of humanity (Preamble), hasn’t actually facilitated consensus as to whether or not space may actually be used for military purposes. Outer space – generally taken as everything more than 100 km above the Earth’s surface – is becoming an emerging arena for any technological shows of force, be it the deployment of spy satellites or the testing of weapons (as was the case, for example, with China’s destruction of one of its old weather satellites by a prototype anti-satellite missile).

The fact that a large number of States have been calling for the adoption of a treaty on the prevention of an arms race in space for decades now, and more recently with renewed vigour, demonstrates the international community’s belief that the existing legal regime is inadequate for halting the encroaching militarization of space. This should serve as a reason to re-examine what existing space law actually has to say on this issue.

No explicit prohibition

The 1967 Treaty regulates a broad range of issues relevant to the exploration and use of outer space and celestial bodies, including the prohibition of subjecting them to national appropriation by claims of sovereignty and the obligation to render all possible assistance to astronauts, the “envoys of mankind in outer space” (Art. IV). However, there is no general, explicit prohibition on ‘militarizing’ space,  except the prohibition of weapons of mass destruction (including nuclear weapons) and the usage of the Moon and other celestial bodies for exclusively peaceful purposes. (The latter is developed further by the less-than-successful Moon Agreement, with its 16 State parties, only one of which is active in space other than by consortium). The very existence of such specific norms would appear to stand a contrario to any claims for the existence of a more general prohibition. In this sense, the regime provided for by the Outer Space Treaty stands in stark contrast to the explicit and clear regime envisaged by Art. I of the Antarctic Treaty with respect to Earth’s southernmost continent.

The only substantive provision of the Outer Space Treaty explicitly making reference to ‘peaceful purposes’ is Art. IV, section 2, establishing a basic legal regime for the use of the Moon and other celestial bodies. However, a number of other binding principles regulating space-faring as a whole are present in other articles, namely: that the exploration and use of outer space be carried out for the benefit and in the interests of all countries (Art. I); that they be done in accordance with international law, including the UN Charter, “in the interest of maintaining international peace and security and promoting international co-operation and understanding” (Art. III); and that States Parties to the Treaty be guided by the principle of cooperation and mutual assistance and conduct all their activities in outer space with due regard to the corresponding interests of all other States Parties (Art. IX). A specific regime of international liability for damage caused by the ‘space object’ of one State Party to the persons or property of another is established in Art. VII; this regime is further developed by the 1972 Liability Convention. It is certain that these provisions restrict the activity of States in outer space – the only issue is to what extent.

Preventing the militarization of space?

There are at least two challenges to interpreting the restrictions imposed by the Outer Space Treaty on military uses of space: first, the question of its wartime application; and second, the content of the above-mentioned norms must be ascertained.

Space law treaties do not make explicit reference to their application in times of armed conflict, and although it can be argued that they were drafted with peacetime relations in mind, their careful analysis indicates that they do not cease to apply in conflict situations. For example, the wording of Art. IV of the Outer Space Treaty leaves very little room for doubt with regard to its wartime application, and most, if not all principles established by the Treaty as guiding the exploration and use of outer space may reasonably be assumed to be general, universal and applicable to all activities of States Parties, including those undertaken in times of armed conflict.

Given that there is no explicit prohibition of all military activity, it is more complex to determine what those principles actually entail. The requirement under Art. IX that States Parties, “guided by the principle of cooperation and mutual assistance”, undertake to “conduct their activities in outer space […] with due regard to the corresponding interests of all other States Parties” is obviously universal in nature. While the terms used do not have the same meaning as ‘peaceful’, they may be read as imposing an obligation to refrain from using space for deploying force against other States. This being said, such an obligation appears to be neither absolute, nor, indeed, does it prohibit the mere presence of military facilities or personnel in outer space or uses that could potentially have a military application. In this regard, the requirement of Art. III is more important.

In the recent UN General Assembly Resolution 69/32, the international community recognizes that the existing legal regime itself does not guarantee the prevention of an arms race in space. However, the resolution reiterates the conscience “that the prevention of an arms race in outer space would avert a grave danger to international peace and security” and reiterates the importance of Art. III and IV of the Treaty. This implies that the international community gives the same importance to the very broad wording of Art. III as it does to the comparatively precise prohibition of placing weapons of mass destruction in space, as contained in Art. IV.

Perhaps the real question does not lie in discerning the meaning of ‘peaceful purposes’, but rather in defining ‘militarization’ itself. Are the terms ‘militarizing’ and ‘weaponizing’ space – the latter also being a word occasionally heard in this context – identical, or do they refer to different activities? If the explicit prohibition on using celestial bodies for military purposes were to be expanded to encompass the whole of outer space, would this also prevent, for example, the use of satellites for guiding certain types of weapons on the Earth? Ardently pacifistic lawyers should always beware arguing the latter, bearing in mind that, for all intents and purposes, the use of satellites for guiding certain weapons can lead to more precise strikes, and therefore less civilian ‘collateral damage’; this is certainly an issue that must be kept in mind when work on a new treaty finally commences.

Space law: A need to legislate?

To summarize, it is very difficult to interpret the Outer Space Treaty as foreseeing a general prohibition on militarizing space. However, what can be argued – and with very good grounds – is that the militarization of space, especially when taken as its weaponization, would very likely be a threat to international peace and security in the sense of Art. III. Such an interpretation implies that all States Parties should refrain from such activities even in the absence of more specific legislation. Furthermore, the regime established by the Liability Convention brings about an additional dynamic to these matters, but this will be the subject of a subsequent post.

Any analysis of the militarization of space should likewise take into account its impact on the environment. The above-mentioned Chinese weapons test was, inter alia, criticized for generating some 800 additional debris in the Earth’s orbit (an increasingly dangerous problem that could lead to a phenomenon known as Kessler Syndrome). In fact, Art. IX of the Outer Space Treaty obliges states to avoid causing adverse changes to outer space or celestial bodies; again, seeing as how testing weapons may or may not be in line with this provision, it’s simply one more reason why a new treaty should be negotiated as soon as possible.

Today there is certainly willingness on the part of many States to engage in talks on these matters – these aspirations should be lauded and supported. However, the fact that a new space law treaty could soon be on the table does not absolve lawyers from the moral, and indeed humane obligation to continue advocating for greater acceptance of a broader interpretation of existing norms. Such efforts should always be guided by the desire to decrease the suffering of innocents, but also to safeguard space as far as possible from the pervasive and very human habit of making war.

Related content

• Why outer space matters: Major Susan Trepczynski with a brief intro on international space law – Intercross blog, 1 November 2016.

• New technologies and warfare – International Review of the Red Cross, Vol. 94, No. 886, Summer 2012.

• New technologies and the modern battlefield – Web portal.