The article is supposed to explore the infl uence of certain space systems on international strategic stability. It is widely accepted that use of the satellites is crucially important in many fields ranging from economy, through scientifi c use to military purposes. Until now the militarization of space took only the form of surveillance, positioning and communication, so it only supports military and intelligence activities here on Earth. But with the advent of space weapons, especially anti-satellite (ASAT) systems, the weaponization of space may come true. If it happens the strategic stability will be in jeopardy, because whole space infrastructure may be easily destroyed either deliberately or by accident. Less of surveillance and worse communication may endanger especially conventional military capabilities of the United States, maybe even forcing them to limit their forward presence. The other direction of strategic shifts are more difficult to predict. Therefore there is an opportunity that leading countries will not decide to pursue space weapons but on the other hand there are many indications that they would do this. Anyway the development with that respect should be closely watched from the perspective of political sciences. Key words: international relations, international security, strategic stability, space, space weapons, ASAT.