The Federal Aviation Administration issued emergency directives on Tuesday evening prohibiting US aircraft from operating over Iran, Iraq, the Persian Gulf and the Gulf of Oman. The three NOTAMs came in response to escalating military activity in the region. Iran launched an attack just hours prior targeting bases that house US troops, among other things.
Following the assassination of Qassem Soleimani near the Baghdad Airport in Iraq on 3 January 2020 the security of the city and the airport remains in question. As a result some commercial airlines made the decision to halt flights. The impact thus far is limited, but could shift as other airlines assess the implications.
The FAA is prohibiting flights over portions of Iranian airspace in a move that could further heighten tensions in the region.