For Eastern Europe's nascent democracies, the acid test is whether they can bring themselves to tolerate opposition. Romania's misnamed National Salvation Front fails it. Challenged by peaceful demonstrators, it has responded with Tiananmen-like ferocity, staining Bucharest with ever more blood.

The rampages in Bucharest come in the wake of flawed elections that gave former Communists who dominate the front a semblance of a mandate. For President Ion Iliescu to contend he is saving democracy by loosing police and armed workers on ''Fascist rebels'' is sheer effrontery, typical of the tyrant he once served.

At a time of national elections in all six former Soviet-bloc countries, this savagery sets Romania apart. Its authors should not doubt the revulsion it arouses - especially since violence could spill into Bulgaria, where former Communist leaders also confront mass demonstrations.

Just as in Beijing, it wasn't Fascists but hunger-strikers who aroused the Romanian regime's wrath. Bucharest's University Square had been occupied since April 22 by demonstrators demanding the resignation of high-ranking former Communists. Until this week, dissidents thought they had a deal with middle-echelon officials to end their protest in return for access to state-run television. On Wednesday, the regime struck without cause. Riot police armed with electric prods cleared the square, burned tents and detained 263 hunger-strikers. Hundreds were wounded when protesters retaliated by storming police headquarters and a television station. Miners armed with clubs were trucked into Bucharest and exhorted to search out dissidents.