The joooooooz did a pretty good job getting across hostile Syrian airspace to take out the North Korean reactor. While detection capabilities have improved dramatically so have counter-detection capabilities.
A MUCH shorter trip; the IDF can strike into Syria pretty much at will, the planes are damned near on the target approach when they cross the border over the Golan. It's pretty much too late for the Syrians to react effectively to an airstrike at the point it leave Israeli airspace. Not like the Syrians know what they're doing versus the Israeli AF anyway, they are pretty much the IDF's bitches in air combat.
But the Israelis would not have as many advantages in attacking Iran, the ECM/counter-ECM gear that has foxed the Syrians so many times is that much additional non-fuel, non-payload weight to lug on the long, circuitous trip to Iran. They may even regard it as too sensitive to risk on a long-distance mission. Being that the Iranians are psycho paranoids, I would not be surprised at all to find out that they had gotten some 'special friends' from the north and the far east to help lay on extraordinary precautions against an Israeli airstrike, which is the biggest foreseeable risk to their project.
One thing the Israelis will be taking into account in deciding what to do is the consequence of failure. A lot of their strength depends on reputation, and if they go with this and it ends in a debacle, it will aggravate their problems rather than solving anything.
