and resume doesn't mean undelete. Pause / resume, and delete / undelete should be kept separate IMHO. So resume should just resume paused campaigns and a new undelete option should allow you to reverse the status of deleted campaigns.
Granted though, it should warn you that you're resuming a deleted campaign. But that's a feature request to save people making mistakes IMHO rather than anything inherently wrong with their UI.
It doesn't make sense to "delete" campaigns in the traditional sense. How would you then get stats on your total spend over time, etc. Those stats are needed, and to remove them would cause even more confusion.
I've been using adwords for years. Never seen a problem with it. This is nothing new, it's been like this forever. It's pretty obvious how it works in the UI :/
Maybe it should alert you if you resume deleted campaigns and ask if you really meant it.
