Send any friend a storyWASHINGTON — Classified war documents detailing secret American and NATO plans for building up the Ukrainian military ahead of a planned offensive against Russian troops were posted this week on social media channels, senior Biden administration officials said. That the documents could be posted on a widely dispersed social media channel, and presumably get into the hands of Russian officials, is a big coup for Moscow at a time when Russia had appeared to be trailing the United States in intelligence gathering in Ukraine. Concerned that sharing their operation plans could also highlight weaknesses and discourage continued American support, the Ukrainians were closely guarding them even as American intelligence was gathering precise details on what the Kremlin was ordering and Russian commanders were planning