And Black resigned.

A clear refutation.

18…Nxd5 fails to 19.Qe4+.

With three strong central pawns for the piece Nakamura soon prevailed.

Black resigned.

This position had already occurred a couple of times in practice. White did not manage to win a single one of these games, and indeed Black appears to have a safe fortress. Obviously White will not be able to create a passed pawn on the queenside. Without that, making progress on the kingside turns out to be impossible.

Looking a little further, it will help if you start searching for ways to keep the h4-knight off-side.

After the text move, the rook and passed pawn turn out to be a dangerous couple in exchange for the two pieces, which is not so strange especially if you consider the knight on h4 – another reason not to go for this knight immediately.