The market really overreacted in regards to the Iran war, misunderstanding the travel business. It's true that high oil prices are going to have an impact on travel. But when travel gets more expensive, people don't give up on taking a vacation, they just choose a different destination.
Booking Holdings income is still going up. Overall the travel industry is not panicking at all about the war. Japan is still getting more and more tourists for example. Flights may be expensive but the yen is still cheap, making it an attractive destination. People are also becoming somewhat conditioned to search for good deals when there are disasters.
Some places and services will suffer from higher oil prices. But Booking Holdings will be collecting its referral fee no matter which destination, airline or hotel you choose. People aren't going to try new booking services because flights got more expensive.