Seems more doable, less likely to incur punishments, and very effective. Greece is hanging by a thread. If Iran fired a test missile over Spain into the Atlantic, they'd hit a double and rack up both Greece and Spain. Or sink a European ship in the Straights of Hormuz. Plenty of things. This is why you don't perpetually kick the can down the road, or stretch the rubber band too thin. You may get away with it in a vacuum, but you expose yourself to exogenous shocks - some of which can be man made.