Complex sentence: By the end of 2011 these incompatible strategies led observers to question the group's cohesion; comparisons were drawn with the divergent motivations of the militant factions of the oil-rich Niger Delta.
Split into simpler sentences: By the end of 2011 these incompatible strategies led observers to question the group's cohesion. Comparisons were drawn with the divergent motivations of the militant factions of the oil-rich Niger Delta.