Maria Carolina's preventatives against Jacobinism were rendered useless in the face of the subversive actives of La Touche's fleet, which was obliged to return to Naples shortly after leaving by a storm. The French sailors, "republican agents", were allowed to land on this occasion, inculcating their anti-monarchical sentiments in the Neapolitans. Upon La Touche's departure, on 29 January 1793, Maria Carolina launched an ineffective offensive against Neapolitan radicals, allowing the most dangerous schemers to escape justice. Why the offensive failed can be explained by the fact that her chief of police, Luigi de' Medici, was secretly a radical himself. Concurrently, Maria Carolina arranged a treaty of alliance with Great Britain, on whom France had latterly declared war. By this treaty, Naples was to contribute four men-of-war, four frigates and four smaller ships, along with six thousand soldiers, to protect commerce in the Mediterranean. In August 1793, following the Siege of Toulon, Naples joined the First Coalition, comprising Great Britain, Russia, Austria, Prussia, Spain, Portugal and Savoy-Sardinia, against France.