Nothing says “I don’t love you” like shooting your partner.
That particularly applies to the numerous places around the world where American special forces are working with local troops, who naturally frown on being blown up by their mentors. As it is, numerous Americans have been killed by friendly fire in Afghanistan and Iraq. How much more difficult is the situation for technologically unsophisticated armies, lacking command and communications equipment, operating alongside U.S. troops.
Hence, U.S. Special Operations Command—and the allied armies they work with—would be grateful for anyone who can come up with a reliable means of stopping fratricide. The idea is similar to Identification Friend or Foe (IFF) transponders on aircraft that emit signals that enable radars to identify these planes as friendly: without them, it would be too easy to mistake a friendly plane as hostile.