The bespectacled fellow who came out of an apartment building on a crowded Madrid street looked like any businessman caught in the pre-Christmas rush. Then police agents swarmed in and arrested him. Their captive, wearing a gray wig, turned out to be Santiago Carrillo, 62, the exiled head of the still outlawed Spanish Communist Party. Seized with him were seven other party executives who had been meeting in the apartment hideaway.
Carrillo's arrest threatened to become an international cause célèbre. Occurring just after a nationwide referendum that overwhelmingly endorsed Premier Adolfo Suarez's...