It is not simply an issue you can just "fix" in my honest opinion
If you make more attack rules, and penalties for suiciding, why don't you just get rid of warring entirely and just have netting
And now i realise your going to respond with some lame post about how warring is the best part of this game, and i agree
But the only way for a small nation to "war" or even effect a big nation, is to well, suicide, and we can't expect everyone to be in a big nation, so we are pretty much back at square one