It is terrorism if you look at it from iran's perspective. Maybe they are just trying to power their cities with nuclear energy. If we really were trying to get the terrorist we would go after saudi. That is where most of the terror money comes from and all the hijacker during 9/11 came from there. However we are saudi's b****.
It can be many bad things. Perhaps it is as bad as or even worse than terrorism. But ultimately, it is inappropriate to describe it as terrorism because the goal wouldn't be to cause terror. It would be to eliminate the reactor. An example of what might qualify as terrorism would be if we bombed Ahmadinejad’s house in order to intimidate them into shutting down the nuclear program.