Make it harder to accidentally delete an attribute name that is in use

On an object's attribute assignments screen, there is a drop down to delete an attribute. If a user accidentally clicks on the hyperlinked attribute, the user goes to the attribute name screen. The screen has a similar layout, and also has a drop down with an option to delete the attribute name. Without paying close enough attention, the attribute name itself could be deleted instead of the attribute assignment.

Deleting the attribute name effectively deletes all the attribute assignments on every object, before the attribute name is deleted. There is no warning that this will happen, and no feedback afterward that this deletion is in process. The only clue is that the UI is unusually slow as it performs a mass deletion.

Maybe there should be a popup to let the user know that this is the attribute name, not the attribute assignment? Or a property to not even allow it through the UI? Or maybe the hyperlink from the attribute assignment to the attribute name should have a popup (going to an attribute name page isn't frequently done once the attribute is set up)?