The head of the Chinese lunar exploration program, Ye Peijian, has remarked that:

the universe is an ocean, the moon is the Diaoyu Islands, Mars is Huangyan Island. If we don’t go there now even though we’re capable of doing so, then we will be blamed by our descendants. If others go there, then they will take over, and you won’t be able to go even if you want to. This is reason enough.

His reference to the Senkaku Islands (Diaoyu  Islands) and Huangyan Island (Scarborough Shoal) suggests that China sees space in terms of astrostrategic terrain: the moon and Mars are places of astropolitical importance, rather than simply the focus of scientific exploration. Just as China sees control of the ‘first island chain’ in East Asia as vital to its maritime security, Ye’s comment suggests that these high grounds in space will bear directly on Chinese strategic interests in the coming decades.

Astropolitics is defined by Everett Dolman as ‘the study of the relationship between outer space terrain and technology and the development of political and military policy and strategy’. It contrasts with traditional geocentric approaches to space power, which focus on how space directly influences terrestrial affairs and downplays the vast astrostrategic terrain in cislunar space (the region between the Earth and the moon).

Astropolitics and astrostrategy are big ideas whose time is coming. The 2020s promise greater commercial and national activity from low-Earth orbit (LEO) to the moon and beyond, shifting mindsets from geocentric to space-centric thinking.

Ye Peijian is clearly thinking long term: Mars is distant and probably won’t be astropolitically significant for many decades, but the moon is more important, given its gravitational proximity to ‘near-Earth space’—the region from LEO out to geostationary orbit (GEO)—and its status as the highest natural ground above Earth’s gravity well.

It’s important to understand the astrostrategic terrain of space. Dolman notes:

What appears at first a featureless void is in fact a rich vista of gravitational mountains and valleys, oceans and rivers of resources and energy alternately dispersed and concentrated, broadly strewn danger zones of deadly radiation, and precisely placed peculiarities of astrodynamics.

Rather than being an infinite emptiness, space is delineated by gravitation and transfer trajectories, which constrain human activities in the same way as strategic maritime choke points. An actor that can control them can control access to resources of great value and strategic significance throughout the remainder of the 21st century.

Dolman relates astropolitics to Halford Mackinder’s early 20th-century ideas about geopolitics, which emerged as new technologies for ships, aircraft and railways were fast transforming advanced economies and thus power hierarchies. The driver for that change was a desire to control strategically important resources to gain comparative advantage over other states.

In the 2020s, there’s likely to be a similar recognition of the potential value of resources on the moon or on near-Earth asteroids, in addition to a requirement to control the LEO to GEO region. Under these circumstances, the traditional geocentric approach to space power will be increasingly challenged.

At the same time, space technology is being transformed through the introduction of lower cost reusable rockets, airborne launch systems and, on the horizon, hypersonic aerospace planes. Getting into space is becoming easier, quicker and cheaper, allowing more states and commercial actors to exploit it for geostrategic and commercial gain. Space is becoming more competitive and more congested as a result. It’s no sanctuary from human competition, and major-power conflict on the high frontier is becoming increasingly likely.

Into this complex astropolitical environment, President Donald Trump’s United States Space Force—another big idea—will emerge and evolve, probably over a similar timescale to the expansion of human activity to cislunar space in the 2020s.

There’s been a good deal of criticism—some thoughtful and some based on a kneejerk derision of Trump—about the idea of a US Space Force. The more thoughtful critiques have highlighted challenges in funding a sixth military force from an already constrained US defence budget. There are legitimate concerns about the need to avoid duplicating organisational structures and current US Air Force missions in space. Critics stress that the formation of a space force could severely disrupt the air force at a time of growing international uncertainty.

There’s also been criticism that a US Space Force would violate the 1967 Outer Space Treaty and related agreements. However, nothing in space law prevents the military use of space or the development of space weapons, provided they aren’t weapons of mass destruction or involve the military use of the moon and other celestial bodies. The Space Force per se wouldn’t violate the Outer Space Treaty, but there’s a growing threat that the treaty may come under increasing strain as major-power competition extends out to the cislunar region.

The formation of the US Air Force, which split from the US Army in 1947, was driven by operational experience in World War II, maturing technology and the strategic importance of the air domain. There’s been a similar maturing of thinking on space as an operational war-fighting domain in recent years, and, like the air domain of the 1940s, the space domain in the next decade will be highly contested. Maybe the space force is an idea whose time has come, and it shouldn’t be dismissed outright without deep consideration of the risks and opportunities.

That means it’s important to understand what’s driving Chinese aspirations. If the Chinese see the space domain in line with Dolman’s astropolitics thesis, Ye’s parallel of the moon and Mars with strategically contested terrain on Earth should make space thinkers in the West sit up and take notice. Control of the high frontier doesn’t need to end at GEO, particularly if the moon and other celestial bodies hold strategic wealth and value, and will be within easier reach by the end of the next decade.

The prospect of major-power competition on the high frontier may extend beyond GEO. Ye is making clear that either China will control the moon and other celestial bodies, or others will. The US and its allies must decide whether Chinese control of this high ground is acceptable. The US Space Force’s mission may be completely different from what the US Air Force currently does in space.