SOVIET JEWS wishing to leave their country stand now at a poignant intersection where the pain of being denied meets a new possibility, but still a restricted possibility, of being allowed to go. Members of their community, including especially those who are well known in the West and who have been particularly insistent about departing, are being allowed out in numbers reflecting the Kremlin's calculation that emigration is a boost to the improvement of Soviet-American ties. But in this period of raised expectations, many would-be emigrants are not being permitted out, and their plight compels concern.

The story of two sisters reported in this newspaper the other day is typical. One sister, Nina Raben, with her husband, Mark Belenky, and their 19-year-old daughter, Masha, had been a refusenik -- as those denied visas are called -- for eight years: sustained by the pride and comradeship that come with the decision to emigrate but forced to pay the society's harsh penalties of harassment, isolation and loss of work and educational opportunity. Only last spring were they allowed to leave; they live now in Fairfax County. But they left behind the second sister, Elena Raben, her husband, Vladimir, and their 9-year-old son, Alexander, who were denied visas. Why would one sister and her family be allowed out and the other not? ''Only during a time of war are families torn apart,'' points out Nina Raben. ''It is not a war now.''

Elena Raben and her family were denied visas -- also after eight years as refuseniks -- on grounds that her father-in-law, a retired engineer who was not asking to leave, had once had access to state secrets. The concept of ''state secrets'' -- a very broad category in the Soviet Union -- distinguishes Soviet emigration policy. Nowhere is it publicly written what state secrets known to a would-be emigrant could keep him or a relative from emigrating. Nor are rejected applicants told what secrets figured in the denial. Mikhail Gorbachev announced in 1985 that secrets could not bar their possessor's emigration after 10 years, but in practice it can be longer.

The limbo of ''state secrets'' is unjust and unfair, and causes anguish and separates families. Emigration procedures desperately need to be touched by the modernization Mr. Gorbachev promises Soviet society as a whole. The forthcoming summit offers him a good occasion to report the change.