The U.S. Navy, like the army and air force, is facing opposition from environmentalists. In this case, a new long range sonar system for tracking submarines hundreds of miles away is accused of killing whales and dolphins. These animals (and several other species) use a form of sonar themselves. Thus these underwater creatures are going to hear the navy's sound signals. As with many environmental disputes, the accusations are not based on solid evidence. Sick whales have been found in the vicinity of navy sonar exercises. The navy says it's coincidence, the environmentalists say it's the navy's high power sonar that killed the animals. This one is likely to be fought out in the courts. What bothers the navy is that a nation like China, which ignores environmental lawsuits, will develop their own version of this technology and gain an edge in underwater warfare.