Although it's often invoked to intercede on an emergency short-term basis, one of the most potent functions of our federal court system is to guide government toward broader policies that make sense for the long term.

That's the case with the intervention of U.S. District Judge Florence-Marie Cooper, whose halt to the use of high-power, midfrequency sonar during Hawai'i's Rimpac 2006 exercises ultimately compelled both the Navy and environmental groups to forge a reasonable compromise.

In the initial ruling, Cooper rightly identified that the federal law required more environmental study in advance of the sonar permit that was issued. But the pragmatic solution in this case — in which a vital military exercise hung in the balance — was reached in the accord the Navy and the National Marine Fisheries Service struck with their legal challenger, the Natural Resources Defense Council.

The agreement made it clear that sonar would be used well outside the newly established federal marine monument and will involve additional monitoring by the fisheries agency.

This should help avert disturbance to marine mammals as well as further the scientific understanding of sonar's environmental effects — adding to the nearly $10 million the Navy already commits to research on this issue. More work is needed to understand various causes of distress to beaked whales and other sensitive marine species.

The experience this year should help guide the Navy and federal authorities toward best practices in future exercises.

The environmental council also is pursuing a separate court action filed last fall that seeks a plan for reducing the impact of midfrequency sonar use in general, not only during specific exercises such as Rimpac. Given the concern about sonar the courts have expressed to date — an earlier settlement restricted global use of a low-frequency active system — it would be wise for all concerned to negotiate another settlement rather than rely on the court system.

Such an agreement should set rational guidelines that could be applied to future sonar use. There's no reason that well-planned military exercises can't be conducted with sensitivity to the marine mammals who live in our oceans.