A declared Guild War cannot be declined or refused, which I find to be rather unfortunate.
Well, that is a understatement if ever I read one..
Mildly so. If it wasn't tantamount to bragging, I'd label myself as a Master of Understatement.
I've been playing since early Chapter 1 and my first main character (long retired) didn't join a guild until lvl 50, specifically to avoid being involved in any Guild Wars. The necessity of joining a guild to progress outweighed my preference of avoiding Guild Wars.
It didn't take very long, though. Some boob in my guild torched someone in WC. The next thing I knew while questing was being shot in the back by someone from another guild that had warred us. (I hadn't noticed or seen the announcement, so...) After the first couple of times getting my butt shot off, a quick trip to my house via HSH rune corrected the problem. And, of course, logging out of the game for the rest of the evening.
As a player and, later, as a Moderator and Game Master, I've never liked the ability of a Guild Leader or officer who happens to be peeved with someone from another guild to have the ability to declare War on that guild and thereby ruin or greatly diminish enjoyment of this game for everyone in the target guild for an hour or so. Especially if multiple wars are declared during an evening, or even a weekend. And I've seen that happen. It's wrong and repeatedly warring another guild can lead to people leaving the game and also truly can be considered harassment.