Here's the second article in this series if you haven't already seen it:
I didn't find any direct references to Pax Christi on Benjamin's website, but I did find a number of references to Ramsey Clark:
I'm also finding sites listing Benjamin with Clark's Pax Christi associate Thomas Gumbleton:
Benjamin and Gumbleton both show up here on a German website against the Iraq embargo:
Initiative gegen das Irakembargo Deutschland
This site includes a link to Clark's IAC:
Einige Internet-Adressen zum Thema Embargo oder Irak
Many of the same names show up on this British anti-embargo site: