Softening up the g6-pawn (and the black kingside as a whole) for a later attack.
5...Qf7 6.Re6! Rxc4 7.Rb7! Qxb7 8.Rxe8+ Kh7 9.Re7 Qb1 10.Kh2 Rxc2 11.Qe3! Qb2 12.Qe6
2.h3?! Ra3! 3.Bc3 hxg4 4.hxg4 Ng6 Black is clearly better – Lputian. In effect White has to look out for both 5...Nxf4 and 5...Qh4.
5.Bd1 Ra6 6.Qb2 Qa8 7.Qd2 Ra2 8.Rb2 Ra1 9.Kg2 Qa3 10.Bg4 Nxd4 11.cxd4 Bb5! 12.Be2 Bxe2 13.Qxe2 Qxc3