...Five hundred and twenty years after the start of the Inquisition, Spain opened the door to descendants of Sephardic Jews whose ancestors had fled the Iberian Peninsula, forced, in order to live in Spain or its colonies, to choose between exile or conversion to Christianity. Or worse.

Top government officials pledged to speed up the existing naturalization process for Sephardic Jews who through the centuries spread in a diaspora — to the Ottoman Empire and the south of Italy; to Spain’s colonies in Central and South America; and to outposts in what are now New Mexico, Texas and Mexico.

Spain’s foreign minister, José Manuel García-Margallo, sought to address his nation’s painful legacy when he revealed the reforms, declaring it was time “to recover Spain’s silenced memory.” But the process is much more complicated than it appears, and some descendants are discounting the offer as useless, or even insulting, as it dawns on them that they are excluded....