The bright sun greets the International Space Station in this photo taken from the Russian section of the orbital outpost by one of the STS-129 crew members, November 2009.
The bright sun greets the International Space Station in this photo taken from the Russian section of the orbital outpost by one of the STS-129 crew members, November 2009
NASA Handout via REUTERS

Last month, the Pentagon outlined plans for Space Force, U.S. President Donald Trump’s proposed sixth branch of the U.S. armed services, charged with protecting American interests in outer space. Vice President Mike Pence, who chairs the National Space Council, heralded the report, describing space as a critical war-fighting domain. The United States increasingly relies on space capabilities that face emerging threats, Pence noted, and he repeated what Trump had declared in June: “It is not enough to merely have an American presence in space; we must have American dominance in space.”

For months, pundits have debated whether maintaining such dominance requires a Space Force. What these discussions often miss, however, is that space security depends at least as much on international cooperation as it does on national dominance.


Space has, in fact, become more crowded, as the Trump administration says. And potential U.S. adversaries are expanding their warfighting capabilities there. As of April, the Union of Concerned Scientists recorded 1,886 active satellites in its online database, an increase of more than a third since 2015. According to one recent report, a thousand small satellites were launched between 2012 and 2017 alone, 104 of them by a single Indian rocket. Many countries have responded to this proliferation of space assets by developing antisatellite weapons. Potential American adversaries have demonstrated their willingness to use such weapons: China used a missile to destroy one of its own satellites in 2007, and Russia pinged a Japanese satellite with a laser in a 2009, in a non-damaging test of its capabilities.  

But because outer space is not just an arena of interstate conflict, a viable American space strategy cannot fixate simply on achieving national dominance. Space is also a global commons, a domain on which all states rely (to varying degrees), and in which they encounter shared threats that require collective security.

Among these shared problems is the proliferation of space debris. Spacecraft travel at tremendous speeds—some 17,000 miles an hour in low earth orbit—such that striking even a tiny fragment can cause catastrophic damage. Just last month, the International Space Station sprang a leak, possibly from a collision with a small object, in what has become a minor international incident. Today more than 29,000 known pieces of space junk larger than softballs orbit the earth, along with another 750,000 larger than peas. Incidents such as China’s 2007 antisatellite missile test, which created more than 30,000 pieces of debris, 3,000 of which are now being tracked, have only made the problem worse. According to scientists, runaway debris accumulation, known as Kessler Syndrome, could render orbital space unusable if left unchecked.

And debris is just one shared threat. Space weather, which includes cosmic rays and coronal mass ejections, among other phenomena, can damage on satellites and disrupt terrestrial power grids. The more earthbound systems depend on satellites, the greater the potential cost of such events. A solar storm of similar magnitude to the Carrington Event, which wreaked havoc on telegraph systems across Europe and North America in 1859, could cause damages totaling in the trillions of dollars were it to occur today. Such an incident—scientists estimate a probability of up to 12 percent in the next decade—would cause a prolonged global crisis indifferent to national borders.

Mitigating these dangers requires that countries work together to further their common interests. Over the decades, a patchwork of global, regional, and national institutions and initiatives has emerged to facilitate international cooperation in outer space. This cooperation includes the sharing of vital scientific and technical information, as well as enhancing cross-border coordination among national agencies. The International Telecommunication Union, for instance, plays a vital role in managing the placement of satellites in geostationary orbit, which allows them to stay in a fixed position over a point on the Earth’s surface, as well as in regulating radio transmissions to minimize interference. Likewise, the International Space Environment Service collaborates with the World Meteorological Organization and other groups to monitor solar and geomagnetic fluctuations and issue warnings regarding dangerous space weather.

The United States is both the leading benefactor and the chief beneficiary of international cooperation in space.

The United States is both the leading benefactor and the chief beneficiary of international cooperation in space. The U.S. Strategic Command’s Joint Space Operations Center tracks orbital debris by drawing on a global web of ground- and space-based sensors as well as information shared under numerous bilateral agreements. The center uses the data it collects to help domestic and foreign spacecraft operators avoid collisions. This service is free of charge, and the United States benefits from a tidier and less hazardous space environment. Meanwhile, U.S. partners abroad furnish vital meteorological data and other resources that support American civil and military objectives. Such interdependence makes it unwise and impractical for any one country, including the United States, to attempt to exert perpetual dominance in space.


Since the dawn of the space age, then, the nations of the world have woven a makeshift tapestry of international cooperation. This fabric is increasingly threadbare, however. At precisely the moment that space is becoming more crowded and conflict-prone, many of the arrangements for governing it are hurtling toward obsolescence.

The Outer Space Treaty (OST), which entered into force in 1967 and remains foundational, has become anachronistic in many respects. Among other provisions, the OST establishes that the exploration and use of space is the “province of all mankind,” prohibits sovereignty claims over space and celestial bodies, and designates states as responsible for national activities there. But it makes no formal demarcation between air and space, lacks a dispute settlement mechanism, is silent on collisions and debris, and offers insufficient guidance on interference with other countries’ space assets. These gaps heighten the potential for conflict in an era of congested orbits and breakneck technological change. At the same time, the treaty’s fundamental principles have been challenged as countries wrestle with the democratization and commercialization of space. The 2015 U.S. Commercial Space Launch Competitiveness Act, for example, recognized the right of American citizens to own asteroid and space resources recovered through commercial activity. Some scholars and governments viewed this as skirting the principle of national non-appropriation, violating the spirit if not the letter of law.

The UN Committee on the Peaceful Uses of Outer Space has adopted four treaties subsequent to the OST. The committee’s unwieldy size and consensus-based decision-making, however, have often made for ponderous discussions and decisions that are dead on arrival. For instance, none of the major spacefaring powers have accepted the 1979 Moon Agreement, the last of the major multilateral space treaties, which would have made celestial bodies and their resources the “common heritage of mankind,” a designation with severe legal implications.

More recent attempts to reconfigure the rules of the road for space have met with mixed success. Negotiating new multilateral treaties has for the most part been a nonstarter, with both the George W. Bush and Barack Obama administrations blocking joint Russian-Chinese proposals for the Treaty on the Prevention of the Placement of Weapons in Outer Space.

From the U.S. perspective, the proposed treaty has many shortcomings. Most important, it focuses on space-based weapons that have yet to materialize, while omitting mention of kinetic, ground-based antisatellite systems that have already wreaked havoc in space. The treaty also fails to define critical concepts, such as “weapons in space” and “the threat or use of force,” and it blurs the line between offensive and defensive weapons systems. The mechanism for enforcing compliance with the treaty’s terms is vague. Meanwhile, the treaty lacks verification measures that allow launch payloads to be inspected, and it does not address the problem of dual use space technologies, which can have both peaceful and military purposes. Finally, any such treaty would need to be negotiated within the consensus-based Committee on Disarmament, notorious for its paralysis.

Countries have exhibited a greater willingness to embrace voluntary measures. Several governments have passed regulation compliant with the UN Debris Mitigation Guidelines, adopted via General Assembly resolution in 2007. The guidelines were designed to help curtail debris-generating antisatellite missile tests of the sort that China conducted. Further measures for improving long-term stability and sustainability in outer space have come through the UN’s standing Committee on the Peaceful Uses of Outer Space and the UN Group of Governmental Experts on Transparency and Confidence Building Measures. The former, established in 1959 in the wake of Sputnik, today oversees implementation of the five relevant UN treaties: the Outer Space Treaty, the Rescue Agreement, the Liability Convention, the Registration Convention, and the Moon Treaty. It serves as the UN’s main repository of scientific and technical expertise, as well as legal analysis, of trends in outer space. The latter, created in 2011 by then UN Secretary General Ban Ki-moon, proposed an array of reforms, ranging from prior notification of space maneuvers to provisions for visits to launch sites, as well as command and control facilities.

These are victories for international cooperation, but much work remains to be done. The amount of orbital junk is still increasing, and international cooperation will be necessary both to minimize the generation of new fragments and to remove existing ones. Countries must also work together to prevent harm from adverse space weather. Most importantly, states have a collective interest in curtailing dangerous space arms races, from which everyone stands to lose.

Unfortunately, efforts to slow the militarization of space, even through informal agreements, face domestic as well as international headwinds. During the Obama administration, the United States championed a non-binding International Code of Conduct for Outer Space Activities. Among other principles, it would have obliged all parties to refrain from interfering with other countries’ space assets, as well as from generating space debris through antisatellite tests on orbiting space objects.

Yet even this declaration of principles was too much for the administration’s critics, raising hackles among Republican senators who argued that it would restrict the U.S. military’s ability to defend the United States. John Bolton, who was then at the American Enterprise Institute, made a similar argument in a New York Times op-ed, written with former Deputy Assistant Attorney General John Yoo, which endorsed perpetual U.S. “primacy” in space. Given Bolton’s current position as Trump’s national security adviser, we are unfortunately unlikely to see the code resurrected any time soon.


The United States remains the world’s foremost repository of scientific expertise and advanced space technology. As such, the country is an irreplaceable leader and patron of outer space cooperation. Continuing to fulfill this role will require a steadfast commitment to working toward collective rather than unilateral security. Such a commitment requires that out of enlightened self-interest, the United States avoid the unnecessary militarization of space. At least some Trump officials may be open to such an approach. The administration recently released a welcome directive on space traffic management, for instance, which emphasized the need for international transparency and data sharing to lower collision risks and handle orbital congestion. The president’s National Space Council should further support international norms and initiatives designed to alleviate orbital congestion, share information, build mutual confidence, and resolve disputes, so that space competition remains within peaceful bounds.

For this to happen, though, the Trump administration must stop calling and striving for American dominance of space. As a still-emerging domain of human activity, one that is shrinking even as its uses expand, outer space demands forward thinking and a willingness to countenance unorthodox ideas. For the administration, this means setting aside retrograde security notions and averting geopolitical collisions in space. It also means leading a United States that is first in setting rules and promoting international cooperation. 

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