In late September, an experienced pilot at low-cost European airline Wizz Air felt anxious after learning his plane would fly over Iraq at night amid mounting tensions between nearby Iran and Israel.

He decided to query the decision since just a week earlier, the airline had deemed the route unsafe. In response, Wizz Air's flight operations team told him the airway was now considered secure and he had to fly it, without giving further explanation, the pilot said.

"I wasn't really happy with it," said the pilot, who requested anonymity from fear he could lose his job. Days later, Iraq closed its airspace when Iran fired missiles on Oct. 1 at Israel. "It confirmed my suspicion that it wasn't safe."