And this is why I am playing Travian.
xD If somebody is sending an army after me and I clock it, I'll either ask my alliance for back up or spend most of my resources on upgrades and send the troops for a 'walk' and send the resources to be given to one of my villages that are not currently being targetted. It results in the raider gaining nothing. :'D
Unless of course, they're attacking, then I have to answer that with force since they could do damage to my actual village :o
@Soul: yeah, I used to play travian ages ago and this is indeed a common tactic, which unfortunately doesnt work in clash of clans. Nevertheless it is possible to get troops from your allies which can in fact, if they are good enough, turn a fight.