The Justice Department has removed top national security officials as part of a widespread purge of senior career leaders across the law enforcement agency, according to people familiar with the decisions who spoke on the condition of anonymity to discuss personnel issues. The transferring of at least three national security officials amounts to a complete gutting of leadership in the highly sensitive National Security Division, which is charged with working with the FBI and other intelligence agencies to protect the nation from threats. It is unclear if the national security officials were provided a reason for their removals. They were...