First and foremost, for Israel. Iran is not Iraq; they have proven this time and time again. Iran is a country whose military is at least as strong as Israel's, and whose soldiers are emboldened to fight until victory or martyrdom; such an enemy is not to be taken lightly. Israeli jets crossing into Iranian airspace should expect stiff resistence, and it is not too much to suppose that a good many of them will not head home after their mission. If Israel thought it had experienced MIA tragedy when Ron Arad fell, let it try to figure out how the country will deal with 5 to 15 such Ron Arads. It will be a very heavy blow to country morale, even if the mission does succeed, which is unlikely. What about the world? Iran's immediate response to an attack will be to shut off oil supplies from the Persian gulf, sending oil prices soaring from $85 today to possibly $200 per barrel. Needless to say, this will completely paralyze the world economy and send it into a deep recession.
from the article: Complex, but not impossible