Is it ever. In fact, even the current conservative Spanish government has nothing to do with Pinochet's arrest. The whole thing is the result of a single judge's initiative, Baltasar Garzsn. He is a very well known judge, with moderate leftist leanings. At first, the Pinochet initiative was dismissed by most (including, sad to say, myself) as a publicity stunt. I guess he showed us.
Two further points. First, the entire Spanish political spectrum supports Garzsn enthusiastically, including the right wing ABC. Second, similar warrants have been issued against the most prominent members of the Argentina juntas.
Enrique