WASHINGTON (AP) — U.S. officials said Monday that improvements ordered by President Joe Biden to strengthen defenses against Chinese espionage helped identify last week’s spy balloon — and determine that similar flights were conducted at multiple points during the Trump administration. White House national security adviser Jake Sullivan said Monday that after Biden took office, the U.S. “enhanced our surveillance of our territorial airspace, we enhanced our capacity to be able to detect things that the Trump administration was unable to detect.” Speaking at the event hosted by the U.S. Global Leadership Coalition, Sullivan added that as part of those...