That claim was given legitimacy by Texas Gov. Gregg Abbott's order last week for the Texas State Guard to monitor the exercises.

"Operation Jade Helm poses no threat to any American's civil liberties," Army Col. Steve Warren, a Pentagon spokesman, said Monday. "Operation Jade Helm is being conducted by Americans – by, specifically, American special forces personnel."

Jade Helm 15 will be one of the biggest peacetime military exercises in six decades. Starting July 15 and lasting two months, thousands of Army Rangers, Green Berets, Navy SEALS and other special operations forces will simulate war missions in mainly remote areas of Arizona, Florida, Louisiana, Mississippi, New Mexico, Texas and Utah.