This week, Republican Presidential candidate Newt Gingrich announced that as President, he would support building an American colony on the moon. According to Gingrich, by 2020, “we will have the first permanent base on the moon… a manned colony on the moon which flies the American flag.” Whilst the idea has been ridiculed in some quarters, its legality has also been questioned (e.g. Newt Gingrich’s dreams of moon colony squashed by 1967 treaty).
So what does international law say about activities on the moon?
There are several international treaties which regulate activity in space. One of the first treaties adopted on this subject was the 1967 Outer Space Treaty which declares in Article I that:
The exploration and use of outer space, including the Moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind.
Outer space, including the Moon and other celestial bodies, shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies.
These principles are repeated in the 1979 Agreement covering the Activities of States on the Moon and other Celestial Bodies.
Yet, it does not follow that bases on the moon are necessarily forbidden. The 1979 Agreement prohibits the establishment of military bases, installations and fortifications (Article 3(4)) but it explicitly permits the establishment of “manned and unmanned stations.” (Article 9(1))
The problem with the plans put forward by Gingrich is the notion of an American colony. What the 1979 Agreement is clear upon is that “the moon is not subject to national appropriation by any claim of sovereignty, by means of use or occupation, or by any other means” (Article 11(2)) and “the placement of personnel, space vehicles, equipment, facilities, stations and installations on or below the surface of the moon, including structures connected with its surface or subsurface, shall not create a right of ownership over the surface or the subsurface of the moon or any areas thereof.” (Article 11(3)) Moreover, the resources of the moon are declared to be the common heritage of mankind (Article 11(1)) which should be subject to an international regime for their exploitation (Article 11(5).
Does this spoil the plans of Newt Gingrich? The obvious response is the the United States is not a party to the 1979 Agreement. Yet, the prohibition on national appropriation is repeated in Article II of the 1967 Outer Space Treaty which is binding on the United States. Although the latter treaty does contain a withdrawal clause, it is highly likely that those provisions relating to the prohibition on national appropriation have become firmly rooted in customary international law given their repetition in a variety of international instruments which collectively have the support of almost all members of the international community. Thus, this is an obligation that cannot be avoided by simply withdrawing from the treaty.