Complex sentence: Nash is enraged by the violation of Navy regulations (and the social impropriety) but Siegel persuades him not to take disciplinary action against Garrett, warning of adverse stories written by correspondents on Tulura (mainly Gordon Ripwell) sympathetic to the enlisted man.
Split into simpler sentences: Nash is enraged by the violation of Navy regulations (and the social impropriety). But Siegel persuades him not to take disciplinary action against Garrett by warning of adverse stories written by correspondents on Tulura (mainly Gordon Ripwell) sympathetic to the enlisted man.