The Islamic State's success in penetrating the Iranian parliament and carrying out a terrorist attack there is indicative of its considerable abilities as well as its determination. In a certain sense, the attack is rather ironic: the Shiites, led by Iran, reinvented the use of suicide as a weapon in Hezbollah's struggle against Israel, and now that same method is being turned against them, on their home turf. Until now, Tehran had not experienced a terror attack, and I believe this is the first time it paid any real price for its war against Sunni Muslims across the Middle East. Iranian military figures and members of the Revolutionary Guard may have fallen in battles in Iraq and Syria, but the home front had been quiet. It seems unlikely that the terrorist attack, bloody as it was, will lead Iran's government or its president to change their aggressive policies toward the Sunnis, but the incident will have an impact. It will be necessary to modify the preparedness of security apparatuses in major cities, especially around sensitive government sites. The government in Tehran cannot allow such embarrassing incidents to continue. To a certain extent, its prestige lies in its ability to provide the average Iranian citizen with both personal and public security, differentiating its citizens from those of many other countries in the Middle East who experience acts of terrorism -- sometimes at Iran's behest -- on a daily basis. The Revolutionary Guard's decision to blame Saudi Arabia for the attack shows how embarrassed it is; it cannot admit that an organization in retreat is responsible. It is easier to blame a country, especially a country known for its harsh treatment of Shiites and Iran. But this accusation could be the first step in an Iranian attempt to respond to terrorism: It has an address, as opposed to having to take vengeance on the Islamic State, which would require Iran to chase the wind in flight. Although it is easier for the regime to blame Saudi Arabia, it could result in a terrorist war between the two countries. Nevertheless, should that be the outcome, the Islamic State group will not regret the move, because in the chaos that engulfs the Middle East today, the enemy of my enemy is not my friend, but rather another enemy. There is no better example of this dynamic than Saudi Arabia and Iran, two hostile countries that are both bitter enemies of the Islamic State. If they end up fighting each other, the organization responsible for this process will claim it as a real success. In any event, the attack is likely not the end or the climax of a bloody process, but just the beginning.