DOHA, Aug. 16 -- Three Iranian Air Force pilots may have been held in secret custody inside Qatar for six months. Or they may not. The dispute at the heart of a bitter new diplomatic rift between Tehran and Doha is, at its core, a conflict over a fact that neither government will yield on: whether three men named Javad Salehi, Abdolmajid Dashtian, and Omran Behraveshian are alive and under Qatari detention.

Iran's military said they are. General Mohammad Bagherzadeh of the Iranian Armed Forces said the three officers were piloting Su-24 bombers when their aircraft were shot down near Al Udeid Air Base, the US military installation in Qatar, during March hostilities. He said the pilots ejected, survived, and have been held by Qatari autho...