It is much too early for Mr. Mikhail Gorbachev to be making the kind of concessions needed for real progress [on arms control]. He can be expected to begin soon reestablishing the Soviet Union's image as a strong, decisive superpower, and look around for opportunities to exploit areas of American weakness. He is not going to come up with any offers on arms control which would affect advantages the Soviet Union has already won. And he may just possibly be hoping that the American Congress (or European al lies) will kill off SDI before research rushes ahead. It will be surprising if even at a summit the Russians were poised to give up their posture of intransigence.