"More than 600 American service members since 2003 have reported to military medical staff members that they believe they were exposed to chemical warfare agents in Iraq, but the Pentagon failed to recognize the scope of the reported cases or offer adequate tracking and treatment to those who may have been injured, defense officials say.

The Pentagon’s disclosure abruptly changed the scale and potential costs of the United States’ encounters with abandoned chemical weapons during the occupation of Iraq, episodes the military had for more than a decade kept from view.

This previously untold chapter of the occupation became public after an investigation by The New York Times revealed last month that although troops did not find an active weapons of mass destruction program, they did encounter degraded chemical weapons from the 1980s that had been hidden in caches or used in makeshift bombs."

C. J. Chivers reports for the New York Times November 6, 2014. [2]