A year of credit monitoring can help an American service member detect identity theft. It cannot tell that person whether a foreign intelligence service is assembling a dossier around the exposed record.

That is the gap raised by the Pentagon’s newly disclosed personnel data breach. A U.S. defense official told ABC News that the incident affected 2.76 million living people and another 294,000 who are deceased. Exposed information included Social Security numbers and details about military and civilian employment.