As Pakistan positioned itself as a diplomatic conduit between Tehran and Washington, it quietly allowed Iranian military aircraft to park on its airfields, potentially shielding them from American airstrikes, according to U.S. officials with knowledge of the matter. Iran also sent civilian aircraft to park in neighboring Afghanistan. It was not clear if military aircraft were among those flights, two of the officials told CBS News. Together, the movements reflected an apparent effort to insulate some of Iran's remaining military and aviation assets from the expanding conflict, even as officials publicly served as brokers for de-escalation. The U.S. officials, who...