Complex sentence: In particular, Ustaše ideologues were concerned with the large Serb minority in the NDH, and initiated acts of terror on a wide scale in May 1941, and by July, the Germans protested the brutality of these actions.
Split into simpler sentences: In particular, Ustaše ideologues were concerned with the large Serb minority in the NDH, and initiated acts of terror on a wide scale in May 1941. Two months later, in July, the Germans protested the brutality of these actions.