Study recommended for 1 kyu or stronger.(Show more of this level)
The hane of is too soft. White puts pressure with and gets an excellent position.
Of course if black would play an atari with at , then white would not hesitate to cut and capture the 2 black stones.
Instead of black should have played at and cut the white group in 2 pieces. The black stone at the right will help him if a fight follows.