In 2019 American administration established the U.S. Space Force – a new type of armed force to protect the U.S. interests in outer space. This, along with the civilian Artemis program, is another signal that shows a renewed American interest in space and the benefits that may result from
its exploitation. As a result of the U.S. actions, a debate has risen among the international community regarding the permissibility of such actions under the current International Space Law. This author focuses on the capability of military forces, such as the U.S. Space Force, in outer space, in the light of The Treaty on Principles Governing the Activities of States in the Exploration and
Use of Outer Space, Including the Moon and Other Celestial Bodies, opened for signature at Moscow, London and Washington, on 27 January 1967. The author analyzes the permissibility of military presence in outer space from the perspective of the above-mentioned treaty, considering the available information about the mission and purpose of the U.S. Space Force. The author mentions the regulations resulting from the Outer Space Treaty, which may affect the placement of military systems in outer space, in particular the provisions imposing on the State-Parties the obligation to use the outer space exclusively for peaceful purposes.