Chess Opening Theory/1. e4/1...d6/2. d4/2...Nf6/3. Nc3/3...g6/4. Be2

=Semi-Classical Variation=

4. Be2
This is a move that can either lead to a transpositon to the Classical Variation with 4... Bg7 5. Nf3 or the aggressive 4... Bg7 5. g4 (Chinese Variation) and 4... Bg7 5. h4 (Bayonet Attack)