Former FBI special agent Nicole Parker joins'Fox & Friends First' to discuss why the U.S. is on'high alert' for Iranian threats inside the country after U.S. airstrikes on three nuclear sites. In times like this, you hear the concern from your neighbors. You talk about it with people at the gym. It's the topic of conversation over morning coffee -- from small towns to big cities -- "Are we going to see an increase in terror attacks here at home?" Now, there are news that Iranian "sleeper cells" pose a dangerous threat. Such cells could carry out attacks on U.S. citizens in retaliation for recent military operations in Iran, it's understandable that Americans are feeling concerned for their safety here at home.