First, Iran is a Shiite country, a huge opponent to the Sunni ISIS. This is unlikely to be an ISIS plot. Iran does support the separate sometimes terrorist Shiite organization, Hezbollah, currently fighting ISIS in Syria. Hezbollah, mainly opposed to the Syrian government, Saudi Arabia and Israel, is totally a creature of post-Shah Iran. Hezbollah has greatly reduced their international terrorist activity, except against Israel and ISIS. Complicated stuff. Next, most of the Iranians in the US have been here for at least 30 years, before Hezbollah, most because of the overthrow of the US supported Shah would have been prisoned or killed had they stayed in Iran. Many family member left there did die. Most are highly educated, and now highly integrated into US culture. Last, this was not a vetted refugee from any war zone. Time will hopefully tell us what his misguided issues were. Let's keep things in perspective, Islam is not our enemy, terrorism is. They are not the same thing.