During my first trip to Iran in 1996, I visited Ayatollah Ruhollah Khomeini’s tomb, a palatial complex abutting a Behesht-e Zahra Iran-Iraq War cemetery about 14 miles south of Tehran. Like many Shiite shrines, it was airy and beautiful. Khomeini’s sarcophagus lay in the center of the complex behind an elaborate silver gate. Iranian pilgrims would push rial — at the time worth something — into his resting area as donations for the shrine and various Shiite causes.

Three years later, I returned, and the silver gate was plexiglassed over. I asked a guard what happened. He said Iranians were putting dog feces in rial notes and contaminating the area. Other donation boxes were further back, but they were largely empty.