Reinstating this would be a good start: The relevant legal change during the Obama administration concerns the Smith-Mundt Act of 1948.

The Original Smith-Mundt Act

The Smith-Mundt Act was enacted during the Cold War to authorize the U.S. government's foreign information programs, such as Voice of America. A key provision of this act was a domestic firewall that prohibited the dissemination within the United States of materials produced by the State Department for foreign audiences. The primary concern was to prevent the government from turning its own propaganda machinery on its citizens.