The United States, Japan and South Korea will launch a series of joint initiatives on technology, education and defense when the countries' leaders gather at a Camp David summit this Friday, according to senior U.S. administration officials. While the summit is unlikely to produce a formal security arrangement that commits the nations to each others' defense, they will agree to mutual understanding about regional responsibilities and set up a three-way hot line to communicate in times of crisis, the officials said. The officials spoke on condition of anonymity. U.S. President Joe Biden invited his counterparts, Japanese Prime Minister Fumio Kishida...