The nation’s top spymaster said on Tuesday that the White House had long been aware in general terms of the National Security Agency’s overseas eavesdropping, stoutly defending the agency’s intelligence-gathering methods and suggesting possible divisions within the Obama administration. The official, James R. Clapper Jr., the director of national intelligence, testified before the House Intelligence Committee that the N.S.A. had kept senior officials in the National Security Council informed of surveillance it was conducting in foreign countries. He did not specifically say whether President Obama was told of these spying efforts, but he appeared to challenge assertions in recent days...