CUBA HAS just provided, in a place called Suriname on the north coast of South America, fresh evidence of its baneful influence on hemispheric affairs. A sergeant kicked out the elected parliament in this rather prosperous (bauxite), little (a third of a million people) former Dutch colony three years ago and set up what seemed to be a tolerant military regime. As civilian opposition to it gathered late last year, however, now-Lt. Col. Desi Bouterse seems to have clutched. On Dec. 8, in a break with his country's peaceful tradition, he took 15 impeccably democratic, unarmed leaders from their homes in the middle of the night and massacred them. The place has been in shock since.

Nobody says the Cubans guided this murderer's hand. But no one can ignore the close contacts he has had with Cuban (and Soviet) officials before and after Suriname's night of the long knives. The Cubans have embraced him, and he, eager for international reassurance, gives increasing signs of embracing them. For Havana, Suriname means success: one more friendly revolutionary government in the Cuban orbit, and perhaps its first presence on the South American mainland. For Suriname, Havana means disaster: it is at least doubtful whether Col. Bouterse would have contemplated a bloodbath, or been able to move the country toward police-state status, without whatever aid he has been able to obtain from Cuba.

The Dutch have halted payments on the immense $1.5 billion in aid they promised Suriname at independence in 1975, and the United States has halted its token aid, too. Suriname, however, has a cushion from its bauxite. It would be good to think that Suriname has enough patriots available to restore the country's freedom before Col. Bouterse or a successor tightens his hold--even his own officers are deserting him so the Cubans may be eyeing a replacement. Meanwhile, democratic countries everywhere should freeze him out.