KEY POINTS
  • A leak of highly classified Pentagon documents has undermined trust among U.S. allies, former U.S. officials and intelligence experts tell CNBC.
  • U.S. authorities on Thursday arrested 21-year-old Jack Teixeira, a low-ranking member of the Massachusetts Air National Guard, in connection with the investigation into the leak.
  • America's control over its most valuable secrets has been thrust into question by the fallout from the most damaging intelligence leak since Edward Snowden's breach more than a decade ago,
America's control over its most valuable secrets has been thrust into question.

An embarrassing leak of highly classified Pentagon documents has endangered intelligence methods, exposed American strategy and undermined trust among U.S. allies, former defense department officials and intelligence experts tell CNBC.

U.S. authorities on Thursday arrested 21-year-old Jack Teixeira, a low-ranking member of the Massachusetts Air National Guard, in connection with the investigation into the leak.