I. Introduction

The use of outer space is developing in two directions. On the one hand, space technology is used in every corner of contemporary human life; on the other hand, the world has experienced accelerating steps of outer space militarization. The traditional military use of outer space has spread from supportive roles such as communication, navigation, reconnaissance, surveillance and early warning at peacetime, to direct war fighting roles such as command & control, warhead identifying, target positioning, bomb guiding, etc. Even worse, outer space is facing an urgent danger of being weaponized and of becoming a battlefield. Humankind is standing at the crossroads of outer space application. The idea of concluding a legal instrument to stop the dangerous military use is wining more and more support and becoming an important step to realize common security in outer space.

II. Challenges and hopes in regulating outer space activities

To be frank, it is a tough issue to deal with outer space weaponization by means of law. Since the 1980s, the international community has experienced a series of frustration both multilaterally and bilaterally. The end of the Cold War provides no impulse to PAROS issue. The Ad Hoc Committee on PAROS has not been established since 1995. There are at least three explanations to such kind of situation:

Political obstacle. With the adjustment of SDI by the US and the shift of focus on CTBT, outer space issue has been marginalized. The re-emerged concern over outer space issue has been confronted with the great change of the strategic framework after the Cold War. The military super power is inclined to pursue security by power rather than by arms control approach, the consideration for military superiority overwhelmed the consideration for strategic stability; the consideration for unilateral security outweighed the consideration of common security.

Military temptation. Advanced technologies are always used first in military field. Some military decision-makers deeply believe that the control of outer space by one country means the acquirement of multidimensional tactic and strategic military superiority. They believe that outer space will finally be weaponized just like sea and air space. With these beliefs in their mind, it is understandable why arms control in outer space is so difficult.

Complexity of technology. Outer space is a medium different in many aspects from land, sea and air space. The unique environment and the development of relative technology are changing the traditional ideas on weapon and the way of using force. The definition of relative terms (such as outer space, outer space weapon, deploy, test, use of force etc.) and verification of the future treaty is complicated. This, in turn, will be an excuse for certain countries to block the relative negotiation.

However, in spite of the political, military and technical challenges, there are some decisive factors that will attract all parties, including the developing and the developed, to negotiate a legal instrument on outer space non-weaponization issue. For its unique physical nature, outer space can not be owned by any individual nation, a peaceful outer space will benefit all, and a weaponized outer space will endanger the interest of all, especially for the countries that rely on outer space assets most. In this outer space era, no country, include the first one who introduce weapons in outer space can be immune from the severe impact if outer space is polluted by debris, all space assets, no matter civil and military, will certainly be at high risk of being damaged.

III. The characteristics of space system and space behavior

In the discussion of outer space non-weaponization, following questions are frequently asked: What is outer space weapon? What is weapon component or weapon system? How to deal with the earth-based weapon with potential of countering space? What kind behaviours could be regarded as use of force? What is the criterion of outer space weaponization? In the environment of outer space, a generally accepted answer can only be given after clarifying the characteristics of space system and space behaviour.
First, most space systems have a dual use nature. It is generally believed that any man made space object with manoeuvrable capability has the potential to be used as weapons. Some space systems are exclusively designed for war fighting, some systems for civil purposes can be transferred for military or weapon uses at wartime. Some space-based components that are supportive systems for civil or general military purposes at peacetime can be used for war fighting purposes. In addition to civil-military and general military-war fighting dual use nature, there is also an earth-sky dual use nature. Some earth-based weapons are designed exclusively for outer space strike; some earth-based systems have the potential of anti-satellite.

Second, the nature of outer space behaviours is also hard to define in the environment of outer space. Like space weapon systems, many behaviours have a dual use nature. Different definition may lead to different legal implications. Take the use of force as an example. The typical way of using force is to destroy something by collision, explosion, or directed energy, but in outer space environment, use of force may take exotic forms. Varieties of non-traditional ways to impose harm on enemy’s outer space assets are currently being discussed, including de-orbiting, jamming, curtaining and other soft killing measures that make space assets’ function temporarily halted. If these non-violent behaviors are conducted at peacetime, it is hard to determine whether military strikes occurred or not. If yes, military reaction may be triggered; if not, compensation for intentional or unintentional damages should be compensated.
Understanding the above-mentioned characteristics of outer space systems and behaviors is important for determining what systems and activities should be prohibited, limited and permitted.

IV. A legal format for outer space non-weaponization

Law works by regulating behaviours and related matters. To stop outer space weaponization, outer space behaviours and weapon systems are two key elements to examine. Given the complexity of weapons and behaviours related to outer space, it is appropriate to address different situations with different legal norms. Prohibitive, restrictive and permissive measures should be created respectively for different systems and behaviours according to their relations with outer space weaponization. Generally, for weapons designed exclusively for outer space use and the obvious military action of, in and from outer space, prohibitive norms should be applied. For weapons with the potential of being used in outer space or space systems with the potential of being used as weapon, or behaviours with dual nature, restrictive measures should be imposed. Other outer space systems that are designed exclusively for peaceful use and ordinary military use, permissive norms should be applied. In terms of behaviors, any form of force in space should be prohibited. And some dangerous behaviours that may harm space assets of other nations should be restricted as well.

V. Drawing lines: A comprehensive approach or a partial one?

A critical question must be answered before drawing lines between outer space weaponization and reasonable military uses, that is, what kind of activities could be regarded as outer space weaponization? Actually, a variety of systems and activities are in connection with outer space weaponization. In deciding the spheres that future legal instrument to cover, political acceptability, technical feasibility must be taken into account. A balance between the prohibited and the permitted items should be carefully addressed. In this regard, there are two approaches that need to be discussed: a comprehensive approach and a partial approach.

1. A comprehensive approach.

Any activities that may lead to weapon deployment or military conflicts in space should be covered, including the activities conducted on earth or in outer space, in the front stage of weapon R&D, test, production, or in the hind stage of deployment and use. It is not only a weapon ban, but also an activity ban. Following items should be included.
A. Weapons and their components

Space-based weapons, including kinetic and directed energy weapons;
Earth-based weapons, including kinetic and directed energy anti satellite weapons;
Earth-based weapons with counter space capability, including missile defence systems;
Space-based weapon components, which are exclusively responsible for target tracking，identifying, guiding and even striking, such as laser reflector, SBIRS-low.
Space based weapon platforms, including spacecraft exclusively designed for harbouring weapons or dual usable space vehicles.
B. Activities relating to outer space weaponization
Research and development of relative weapons;
Flight test of relative weapons;
Earth deployment of relative weapons;
Space deployment of relative weapons;
Use of force in or against outer space.

Obviously, this is an ideal but too ambitious solution to outer space weaponization issues. There will be too many terms and grey areas to be defined. Considering the contemporary political and scientific conditions, to conclude such a comprehensive legal instrument seems to be a time-consuming and long process.

The partial approach

Partial approach does not pursue a comprehensive ban of all outer space weapons and related activities, it focuses on some areas where breakthroughs can be easily made in stopping the urgent danger of outer space weaponization.

One idea is a selective weapon ban with an indirect behaviour ban. The idea of ASAT ban has been proposed in the early 1980s. Proposals on space-based weapons ban are recent moves. One difficulty with these moves may be the attempt to cover the whole process of R&D, test, production, deployment and use of them, which is just as difficult as the comprehensive approach to realize. Moreover, for the causality between different weapon systems (especially between space weapons and counter space weapons), it seems illogical and impracticable to prohibit certain categories of weapons while permitting others.
The selective behaviours ban is another solution. The working paper entitled “Possible Elements for a Future International Legal Agreement on the Prevention of the Deployment of Weapons in Outer Space, the Threat or Use of Force against Outer Space Objects” (CD/1679), which was put forward jointly by China, Russia and other 5 nations in 2002 is an attempt of this approach. According to the paper, two key behaviours will be prohibited:

Deployment of weapon in outer space;
Use or threat use of force against outer space.
Different from the comprehensive approach, the Joint Working Paper is carrying out an end-control strategy, holding the last line in stopping outer space weaponization while temporarily putting other things aside. The proposal is designed to slide over some tough issues such as definition and verification. Considering the current political and technical situation, the joint proposal provides a practical solution to the current danger in outer space weaponization.
Of course, the Joint Working Paper shouldn’t be regarded as a perfect one. It is rather an activity ban than a weapon ban. Neither does it deal with the front stage of weaponization like weapon research, development and test, nor does it provide detailed definition of the term of use of force. Nevertheless, it covers the key points of preventing outer space weaponization, meets the urgent needs, and could serve as a platform to hold valuable proposals together. Both China and Russia expressed that the proposal is open for further development.

VI．Conclusion

Regulating military activities in outer space is an issue involving political and security concerns, and rests with economic affordability and scientific feasibility. Faced with the coming danger of outer space weaponization, many valuable proposals have been proposed. Although each of them has its own perspective and emphases, most of them deserve serious considerations so long as they are positive steps toward the non-weaponization of outer space. Under the current situation, the partial approach and behavior ban seem to be more practical compared with the comprehensive approach and a weapon ban.

Of course, there is no simple solution to the problem like outer space issue that bears so much security and development interest of nations. The development of science and technology brings challenge to outer space issues, especially when law-making process is involved. In space era, more and more countries will acquire capability of entering outer space, more and more activities will be conducted in outer space. Principally speaking, all countries have the equal right to use and entering outer space, the prevention of outer space weaponization is just a way to protect this right. This is the fundamental driving force in promoting non-weaponization of outer space, and the fact that there is no weapon in outer space provides a window of opportunity for it.
Finally, it should be pointed out that no panacea exists in this contemporary world. There are always issues that even law can not solve. The spirit of self-restriction, mutual trust and cooperation in the form of a code of conduct, confidence-building measures are also important.