Responsable de vs Responsable por

[fglorca]

Crees que los gobiernos de los países occidentales son responsables por el radicalismo islámico?

Is the use of por incorrect here?
Should we use de (del) instead?

[aleCcowaN]

es responsable de

I'd only use "por" when responsable is a noun meaning "being the cause of something, then being blamed of credited for it", what is pretty much an anglicismo.

The only correct use of "por" in Spanish I reckon is like this:

"Como garante, es responsable por las deudas del avalado", meaning the guarantor is not the cause of the debt ("responsable de") but takes the place of the debtor in case of default.