Anarres has no boats whatsoever so I know he can only attack by land. Amphibious is also not researched yet (although anarres could be researching it - unlikely imo - china could also be researching it but as yet no-one has.) Besides as Aggie says rails make attacking a beachhead very easy. Also the second anarres starts building transports I build destroyers
It is a long way round for either of us to do any sea landings too, I'll attach the minimap so you can see what I mean.
The 'raze and burn' method I have used does limit my own options for attack, but having failed to forest the border I think it was the sensible option (hmm... yes I should have forested it in hindsight, I am very inexperienced at modern or late industrial warfare even in solo play and it shows!)
The cities of mine I have weakened are not core so I'm not too worried about the marginal loss in productivity - it amounts to a few gpt lost in scientists/taxmen at most.
The onus is now on anarres to attack as I have the lead in land and I *think* in research/productivity. Anarres also seems to think that if we sit it out I will win (although this could be a bluff, who knows...) I am still looking at it trying to think what I would do in anarres position, no doubt he will investigate seville and see the 50+ infantry there. Hmm... I can't wait to get the turn back!! Maybe the game will be decided in the next few turns...