Fratricide continues to plaque the battlefield.

• Author: Kennedy, Harold

Friendly-fire casualties always have been an unavoidable part of war, and despite years of effort and many millions of dollars for research and development, they continue to occur.

During the first Persian Gulf War, friendly fire incidents caused about 17 percent of U.S. casualties. Following that experience, the Defense Department launched several programs to address combat identification. Technology demonstrations began in 1996, and several systems are at various stages of development.

The blue force tracking system, for example, has been installed in more than 1,200 combat vehicles, combat posts and helicopters for operations in Iraq and Afghanistan. The BFT system consists of a computer, satellite antenna and Global Positioning System receiver. Blue force tracking is useful to battlefield commanders, but it does not prevent fratricide, Marine Lt. Gen. James T. Conway, then-commander of the First Marine Expeditionary Force, told Pentagon reporters.

"Blue force tracker tells you where units are in general design," he said. "It does not solve the problem of blue on blue fratricide." The battlefield target identification system provides that capability, but it is expensive. Individual units cost between $15,000 and $25,000 apiece.

"We're...