Re: Why was Garak allowed to stay on DS9 (Terok Nor)
Garak didn't establish the tailor shop until the Cardassians abandoned the station and Starfleet took over operations. Sisko allowed him to stay, on the chance that he might have access to sensitive information. Since he had Starfleet's approval, that might have been enough for the Bajorans to avoid making trouble.
Dr. Howard, Dr. Fine, Dr. Howard: For duty and humanity! --Men in Black (1934)