Of the sixteen nations that make up the Middle East, seven have actually seen significant spikes in their Catholic population since 1980: Saudia Arabia, Bahrein, the United Arab Emirates, Kuwait, Oman, Qatar, and Yemen. All are part of the Arabian Peninsula.
Saudi Arabia is an especially interesting case. Home to the holy Islamic sites of Mecca and medina, it also now contains the second largest Catholic community in the Middle East, with what the Vatican estimates at 1.25 million believers, though some experts believe the real number may be closer to almost two million. Even considering merely the official count, Saudi Arabia trails only Lebanon’s more than two million Maronites in terms of Catholic population....
The sudden rise of a large Christian minority in nations where Islam is effectively the state religion has made religious freedom a signature cause for church leaders, and not just in the Middle East but also in the countries of origin of these migrants.
John Allen, "Beyond exodus, a Christian influx in the Middle East"