Environmental groups persuaded lower federal courts in California to impose restrictions on sonar use in submarine-hunting exercises to protect whales and other marine mammals.
The Bush administration argued that there is little evidence of harm to marine life in more than 40 years of exercises off the California coast.
Chief Justice John Roberts wrote the majority opinion, which was joined by Justices Samuel Alito, Anthony Kennedy, Antonin Scalia and Clarence Thomas.
The court did not deal with the merits of the claims put forward by the environmental groups. It said, rather, that federal courts abused their discretion by ordering the Navy to limit sonar use in some cases and to turn it off altogether in others.
