DECLASSIFIED - THE SECRET SHARERS

MASS SURVEILLANCE AND SOCIAL MEDIA ARE CHANGING THE SPY GAME. INSIDE AMERICA'S SEARCH FOR A SMARTER WAY TO USE INTELLIGENCE

- MASSIMO CALABRESI

ON THE AFTERNOON OF SEPT. 27, A BALKANS EXPERT AT THE WHITE HOUSE GOT A DISTURBING CALL FROM A U.S. INTELLIGENCE AGENCY.

Serbian forces were massing along the length of their country's border with Kosovo, where NATO has kept an uneasy peace since a bloody war of secession in 1999. Three days earlier, more than two dozen armed Serbs had killed a Kosovar police officer in an attack. Now Serbia was deploying heavy weapons and troops. "We were very worried that Serbia could be preparing to launch a military invasion," says one National Security Council (NSC) official.

The question was what to do about it. Months of mounting tensions in a remote corner of southeastern Europe had not received much attention in the media. Diplomatic efforts by the U.K., Italy, and other countries with troops on the ground in Kosovo had failed to calm the situation. In Washington, attention was focused on chaos in Congress; in much of Europe, the top priority was marshaling continued support for Ukraine. So as part of an effort to pressure Serbia to back down, U.S. National Security Adviser Jake Sullivan approved a request from his Europe team to declassify elements of the Serbian buildup for public release.