In 1983 the United States invaded Grenada. Army units found that their radios could not talk to Navy ships offshore. Colin Powell later said the invasion “succeeded, but it was a sloppy success.”
Grenada was one of the reasons for a new law, the Goldwater–Nichols Act. President Ronald Reagan signed it on October 1, 1986. Its purpose was to fix problems caused by rivalry between the armed services. One rule shapes the path to the top. An officer who wants to become a general or an admiral must first serve at least one tour of joint duty with another branch.