The world's largest Internet search company and the world's most powerful electronic surveillance organization are teaming up in the name of cybersecurity. Under an agreement that is being finalized, the National Security Agency would help Google analyze a major corporate espionage attack that the firm said originated in China and targeted its computer networks, according to cybersecurity experts familiar with the matter. The objective is to better defend Google -- and its users -- from future attack. Google and the NSA declined to comment on the partnership. But sources with knowledge of the arrangement, speaking on the condition of anonymity,...