Seumas Milne travels to Caracas to meet Nicolás Maduro, the late Hugo Chávez's successor as president of Venezuela. Two months of civil conflict has left dozens dead, but with the protests appearing to ebb, Maduro is in defiant mood, convinced he knows who is behind the unrest – and what their ultimate goal might be. Maduro speaks candidly on subjects ranging from Edward Snowden to John Lennon