Yesterday's ISIS twin attacks in Tehran strongly indicate Iran has a problem, although this is not the first ISIS attack in country.

From an ICSR commentary by Charlie Winter:
In sum, this attack against Iran makes strategic sense for the Islamic State in the same way that attacking the United States on 9/11 made strategic sense to Usama bin Ladin.

In the next few days, people will be wondering where this operation came from. Even if the attackers turn out to be foreign nationals, they will have required extensive support from a local network to execute something like this.
Link:http://icsr.info/2017/06/icsr-insigh...-implications/

The Soufan Group's commentary appears to highlight the implications for the USA, following the strong "tilt" to Saudi Arabia and the official note of condolence had a barb within:
We underscore that states that sponsor terrorism risk falling victim to the evil they promote.
Link:http://www.soufangroup.com/tsg-intel...-strikes-iran/