Complex sentence: Trade had also developed between the Punic cities and Etruscan ones, and Carthage had treaties with the Etruscan cities to regulate these activities, while mutual piracy had not led to full blown war between the powers.
Split into simpler sentences: Trade had also developed between the Punic cities and Etruscan ones, and Carthage had treaties with the Etruscan cities to regulate these. Piracy had not led to full blown war between the powers.