1. Kazuto Suzuki Hokkaido University kazutos@juris.hokudai.ac.jp
A Japanese Perspective on Space Deterrence and the Role of the US-Japan Alliance
Kazuto Suzuki
Hokkaido University

2. Space systems are… Critical for socio-economic welfare
Indispensable for modern military systems
Vulnerable to intentional and unintentional damage
Difficult to defend; difficult to deter attacks upon
Most effectively defended through use of non-space means to increase the costs of attack

3. Vulnerabilities in Space
Domain constraints do not permit substantially meaningful physical protection
High velocity due to orbital speeds of approximately 28,000 kilometers per hour mean virtually any impact can kill a satellite
Space objects, human-origin debris, intentional attacks
Solar flares, electromagnetic pulses also threats

4. Anti-Satellite (ASAT) Attacks
Incentives to attack may be substantial:
Space assets are valuable, scarce, vulnerable
Attacks are non-lethal (hence possibly seen as less escalatory), difficult to attribute, and could accord big first-mover advantages
Attribution can be difficult due to blind spots
Kinetic ASATs: create large debris clouds
International condemnation of China after 2007 test

5. Non-Kinetic ASAT Attacks: Cyber Attacks on Space Systems
Taking over satellites via hacking is possible
Command and control systems for commercial and civilian satellites are relatively vulnerable
Taking over a satellite can make it a space weapon
Radio-frequency problem:
Not enough bandwidth for encrypted transmission leads to use of open frequencies which are more vulnerable

6. Non-Kinetic, Non-Cyber ASAT Attacks
Methods include:
Jamming: Interferes with up-link/down-link communications by overpowering the signals through radiofrequency interference so as to prevent transmissions from getting through
Spoofing: Intentionally feeds false information to devices or ground-based receivers by intercepting and overriding weak signals traveling between space and earth
Dazzling: Temporarily or permanently damages functions of reconnaissance satellites using directed energy (lasers)
Rendezvous and docking technology (also known as: killer satellites)

7. Deterrence in Space is Very Difficult
Tit-for-tat is not an attractive option:
Different degree of dependency on space for various actors
Creation of space debris if kinetic attacks employed is also unappealing
Deterrence by denial is difficult:
Shooting down all the ground-based kinetic attacks—costly, hard
Protecting all radio transmissions—very hard
Protecting all sensors—very hard

8. Deterrence in Space?
Life expectancy of satellites is long, posing challenges for modernizing space asset architectures
Space-based assets can be decades-old
Upgrading hardware to meet new challenges almost impossible
Software upgrades often limited by hardware capacity
Attribution problem:
Knowing the real motivations for actions in space extremely difficult
Satellite failure could be caused by malfunction, debris

9. A Tallinn Manual for Space?
A non-binding set of rules drafted by experts from around the world for use in applying international laws of armed conflict to cyberspace
Tallinn Manual 2.0:
Updated version suggests military retaliation to cyber-attack is not legitimate unless authorized by United Nations
If attack perpetrated by non-state actor, victim requires consent of state where non-state actor is based to retaliate
MILAMOS: Tallinn Manual for space is now being drafted

10. The Role of the U.S. – Japan Alliance in Space Deterrence
Increasing transparency and shaping norms:
Space Situational Awareness (SSA)
Information sharing with international community
International rule-making
Resilience/deterrence through (a measure of) denial:
Increasing interoperability for replacing and recovering assets
Deterrence through punishment:
Prepare and plan for military actions to convince adversaries not to take actions against our space assets

11. Conclusions
Importance and vulnerability of space assets needs to be better understood
Especially in Japan
Alliance plays key roles for:
Transparency
Resilience
Deterrence through punishment
Space attacks cannot be deterred by space means alone
Deterrence in space requires cross-domain deterrence