Piled-up clauses

Piled-up clauses
 

Here is some free-form paragraph that shows how flexible Spanish is (sometimes too flexible ... and forgiving).

This is kind of a comprehension excercise. Who is the subject of this paragraph?

In English, this would appear written by someone ignoring rules of grammar. It should be three sentences with three separate but related subjects.

Surprisingly, the paragraph has only one subject, and although it's awfully constructed I don't think there's any mistakes in grammar just abuses.

"Creo que la permanencia del terrorismo etarra es un hecho manipulado por quienes no reparan en métodos a la hora de conquistar el poder. "

This is the core of it. Though the subject is the writer, it clearly points to "them", the usual subjects, you know, the ones that eat babies in pizza parlor basements and control the space lasers that throw hurricanes in the path of the patriotic god-fearing people.

Yes, the whole of it has only the one subject (I, the author).
It is, of course, sprinkled with clauses, each having their own subjects, as is necessary.

The whole of it can be written in English the same exact way, but with em dashes substituted for the hyphens and surrounding spaces, for better appearance.
Other than that, there is nothing wrong with what is written, in either language.
We don't tend to speak that way, though.
The way you reworded it last is more likely what we would say, and then all that other stuff could be brought up in further dialog.

You guys are right, but I can't help but seeing three subjects. They are, (yo) creo, el hecho y dolor de las víctimas. I can see how they can be objects rather than subjects in this awfully written sentence.

It's the typical obfuscated paragraph that intends to provoke a reaction in the reader while it hides it being just a baseless personal opinion. Regretably, the Spanishphere also has its own Margas Sastres Verdes.