Send any friend a storyWASHINGTON — A new batch of classified documents that appear to detail American national security secrets from Ukraine to the Middle East to China surfaced on social media sites on Friday, alarming the Pentagon and adding turmoil to a situation that seemed to have caught the Biden administration off guard. The latest documents were found on Twitter and other sites on Friday, a day after senior Biden administration officials said they were investigating a potential leak of classified Ukrainian war plans, include an alarming assessment of Ukraine’s faltering air defense capabilities. But what is going on with these American documents, he added, “is still pretty unclear at the moment