What's the idea behind delaying capturing the rook (25...Rd2) in Hug–Spassky (1973)? I've been studying a series of games featuring the King's Indian Attack and in Hug–Spassky (1973)[1], I don't understand why White delays capturing the rook after 25...Rd2.
Why play 26. Nd3?
Is White avoiding the loss of tempo after (26. Qxd2 Qd8) or (26. Qxd2 Rad8)?
Instead, White plays 26. Nd3 prompting 26...Rxe2. I must be missing something since I don't see the idea behind 26. Nd3.
[Title &quot;Hug (2440) - Spassky (2655), 1973&quot;]
[FEN &quot;rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1&quot;]
[startply &quot;50&quot;]

1. Nf3 d5 2. g3 { A07 King's Indian Attack } c6 3. Bg2 Bf5 4. O-O Nf6 5. d3 e6 6. Nbd2 Be7 7. Qe1?! { (0.55 → -0.05) Inaccuracy. Nh4 was best. } (7. Nh4 Bg4 8. h3 Bh5 9. g4 g5 10. Nhf3 Bg6 11. Ne5 Nbd7) 7... h6 8. e4 Bh7 9. Qe2 O-O 10. b3 a5 11. a3 c5 12. a4 Nc6 13. Bb2 Re8 14. Ne5 Nd4 15. Qd1 Qc7 16. Nef3? { (0.00 → -1.29) Mistake. f4 was best. } (16. f4 Rad8 17. Kh1 Nd7 18. Ng4 Nf6 19. Ne5) 16... dxe4 17. dxe4 Red8 18. Re1 Nxf3+ 19. Bxf3 c4 20. bxc4 Bb4 21. c3 Be7 22. Qe2 Nd7 23. Nb3 Ne5 24. c5?! { (-1.33 → -1.93) Inaccuracy. Nd4 was best. } (24. Nd4) 24... Bxc5 25. Nxc5?? { (-1.77 → -4.79) Blunder. Bg2 was best. } (25. Bg2) 25... Rd2 26. Nd3 Rxe2 27. Bxe2 Nc4 28. Bf1 Qc6 29. Bc1 Bxe4 30. Nc5 Bd5 { White resigns. } 0-1

[1] Game with annotations by lichess.org
Why play 26. Nd3?
Is White avoiding the loss of tempo after (26. Qxd2 Qd8) or (26. Qxd2
Rad8)?

No, the idea behind Nd3 is to limit the losses. Black would respond to 26. Qxd2 with Nxf3+ forking the king and queen.
[fen &quot;r5k1/1pq2ppb/4p2p/p1N1n3/P3P3/2P2BP1/1B1rQP1P/R3R1K1 w - - 0 1&quot;]

1. Qxd2 (1. Nd3 Rxe2 2. Bxe2 Nxd3 3. Bxd3 {and white has limited the losses}) Nxf3+ 2. Kg2 Nxd2

After the sequence starting with Nd3 white is down a queen in exchange for a rook and a bishop. After Qxd2 white ends up down at least a queen for a rook.