The United States is preparing its armed forces for conflict that could stretch from the ocean floor to the vicinity of the Moon, according to the nation’s top military adviser. Speaking at the Air, Space and Cyber Conference outside Washington, Gen Dan Caine, chairman of the Joint Chiefs of Staff, told service members and industry leaders that the US must adapt now so it “is prepared to fight, endure and win … from the seabed to cislunar space”. The remarks came shortly after the Air Force disclosed that it has already fielded on‑orbit space control weapons, marking the first public acknowledgement of deployed weapons beyond Earth’s atmosphere.
From Seabed to Cislunar: Caine’s Vision
Gen Caine used the term cislunar to describe the region between Earth’s surface and the Moon, a zone that is increasingly seen as the next frontier for military operations. He argued that the armed forces must broaden their readiness to cover every domain, from underwater theatres to the lunar neighbourhood. The statement underscores a shift in strategic thinking, where traditional battlefields are being supplemented by the vast expanse of space that surrounds our planet.
Space Force Expansion and New Weapon Systems
The newest branch of the US military, the Space Force, which was established by President Trump in 2019, is already organising itself for combat in and around the Moon. Lt Gen Gregory Gagnon, head of the Space Force’s Combat Forces Command, told reporters that potential adversaries are looking to turn space into a battleground. He added that the intelligence community has warned that nations such as the People’s Republic of China are actively pursuing activities in space, prompting the US to react.
Gagnon also announced plans to double the size of the Space Force over the next five years, aiming for roughly 25,000 personnel. About two‑thirds of that growth would be directed toward the Combat Forces Command, signalling a clear focus on operational readiness for space‑based engagements. Earlier in the same conference, Air Force secretary Troy Meink revealed that the US has deployed “on‑orbit space control weapons”, a capability that had previously remained undisclosed.
International Reactions and Treaty Concerns
China’s response was swift. Foreign ministry spokesperson Guo Jiakun stated that Beijing “always upholds the peaceful use of outer space, maintains outer space security and opposes the weaponisation, militarisation and an arms race in outer space”. He urged the United States to halt its expanding military preparations beyond Earth’s atmosphere.
The announcements have reignited debate over the 1967 Outer Space Treaty, to which both the US and China are signatories. The treaty declares that celestial bodies, including the Moon, must be used exclusively for peaceful purposes, prohibits the placement of nuclear weapons in space, and holds states liable for damage caused by their space objects. Critics warn that deploying weapons in cislunar space could contravene these long‑standing commitments, while supporters argue that deterrence requires a credible presence in the emerging domain.
Why it Matters
The US military’s open preparation for combat around the Moon signals a new era in which space is no longer a sanctuary for scientific endeavour alone but a potential theatre of conflict. If the Space Force doubles in size and deploys operational weapons beyond Earth’s orbit, the strategic balance among nations could shift dramatically, prompting rivals to accelerate their own space‑based capabilities. At the same time, the move tests the durability of international agreements designed to keep space free of weapons, raising the risk of a costly arms race that could extend humanity’s rivalry far beyond the planet’s surface. The coming years will reveal whether deterrence or diplomacy prevails in this newest frontier.
