Complex sentence: The purpose of Operation Septentrion was "reaffirming the sovereignty of Afghan security forces in the north of the Uzbeen Valley," according to a French military spokesperson, and also to plant the flag of Afghanistan in what was called a key strategic village.
Split into simpler sentences: The purpose of Operation Septentrion was "reaffirming the sovereignty of Afghan security forces in the north of the Uzbeen Valley," according to a French military spokesperson. The operation also intended to to plant the government's flag of Afghanistan in what was called a key strategic village.