I like the idea of it only being possible if the leaders of both alliances forfeit the war. We're pretty high up in the ranking and sometimes we get a war against an opponent where we can win tiny amounts of glory. There is no question of who will win and it is just as boring for us as it is for them. Generally when there are massive mismatches the bigger alliance is just as annoyed as the small one (unless you can win lots of glory with basically no effort but that basically never happens). What's the point of wasting two days to win 7 glory? If both leaders forfeit the war within the first hour or so search will automatically start again and neither one gets or loses glory (why neither team should get or lose glory is the same explanation as in 1) below).
If one alliance could unilaterally forfeit the war the following scenarios are possible:
1) Glory gets assigned as if the other alliance had won: The big ones would automatically rise in the ranking like crazy because small outmatched opponents would just forfeit, not caring about the 30 glory they might lose. Now this happens 4-5 times in one evening the big alliance would have gained more than 100 glory without doing anything in a single day.
2) No glory get assigned when forfeiting: Whenever you think your chances are not good and too much glory is at stake you'd forfeit the war without any penalty. We'd all be searching wars forever hoping the opponent doesn't forfeit when we're slightly stronger while immediatly forfeiting ourselves when the opponent seems slightly stronger.
3) The forfeiting alliance loses glory but the other one does not get any: This would basically be a forfeiting penalty. The problem with this one is that the big alliances would not earn any glory anymore. If we're completely outmatched and know we'll lose 300 glory this war, we'd rather forfeit and lose the glory... at least the opponent doesn't get it.
4) the other alliance gets glory but the forfeiting one does not lose any: I guess the problems with this one are self-evident.
Thus, both alliance have to mutually agree to forfeit, which wouldn't really be forfeitting but rather some mutual agreement that there was a mismatch. Only sensible thing it seems.