4.Nd4 Ne7 5.b3 Qb7! , heading for e4.

White's attack has been neutralized.

Preparing ...Nbd7-f8 to reinforce the kingside defence.

2.Nf3 Nbd7 3.Rad1 seems more active, when Black could prefer 3...b6 followed by ...Bb7 in order to conclude his development.

Preparing ...Ng6-f4 with an even game.

Prophylaxis against the plan of 1...Ne7, heading for g6.

Now that his plan no longer works, Black is limited to defensive actions. It also becomes evident that the ...g6-g5 advance has just produced weaknesses.

1...Ne7 can be met by 2.Qb6! , forcing a queen exchange and winning one of the pawns at b7 and d6.

In view of the threat 5 Ne4, the rook has to retreat.