HAVANA (AP) — For half a century Fidel Castro seemed to be everywhere in Cuba — inspecting factories, farms and offices, expounding to the press and zooming to the scenes of natural disasters to direct the minutest details of the response.

His brother Raul was a military man who operated from behind the scenes, rarely making speeches and going long stretches without appearing in public, even as he attempted historic reforms of Cuba's economy and foreign policy.

A month after taking office, the Castros' successor as president of Cuba has broken from the immediate past, and made clear to Cubans...