I did some shallow wikipedia digging and came up with this:
Among its principles, it bars States Parties to the Treaty from placing nuclear weapons or any other weapons of mass destruction in orbit of Earth, installing them on the Moon or any other celestial body, or to otherwise station them in outer space. It exclusively limits the use of the Moon and other celestial bodies to peaceful purposes and expressly prohibits their use for testing weapons of any kind, conducting military maneuvers, or establishing military bases, installations, and fortifications (Art.IV). However, the Treaty does not prohibit the placement of conventional weapons in orbit.http://en.wikipedia.org/wiki/Space_treaty
That was the only ratified space treaty I could find in my shortsighted search.