still wear the Magen David. To enable the MDA to become a fully recognized and participating member of the International Red Cross and Red Crescent Movement, Protocol III was adopted. It is an amendment to the Geneva Conventions relating to the Adoption of an Additional Distinctive Emblem and authorizes the use of a new emblem, known as the third protocol emblem or the Red Crystal. For indicative use on foreign territory, any national society can incorporate its unique symbol into the Red Crystal. Under Protocol III, the MDA will continue to employ the red Magen David for domestic use, and will employ the Red Crystal on international relief missions. Modern day Medical personnel from most western nations carry weapons for protection of themselves and their patients but remain designated non-combatants, wearing the red cross, crescent or crystal. In the United States Armed Forces, MEDEVAC Vehicles will display a large Red Cross on a white background; however, ground forces do not display this due to increased targeting of medical personnel by insurgents in Iraq and Afghanistan. Traditionally, most United States medical personnel also wore a distinguishing red cross, to denote their protection as non-combatants under the Geneva Convention. This practice continued into World War II. However, the enemies faced by professional armies in more recent conflicts are often insurgents who either do not recognize the Geneva Convention or choose not to adhere to it, and thus readily engage all personnel, irrespective of non-combatant status. As their non-combatant status is not respected, many US medics no longer wear non-combatant markings. This can enable medics to be used as medically trained soldiers, fighting aggressively rather than just in self-defence. Combat Medics in the United States Army and United States Navy Hospital Corpsmen are virtually indistinguishable from regular combat troops, except for the extra medical equipment they carry. The modern-day interpretation of the U.S. Army doctrine requires medics to carry one primary weapon and, if possible, a secondary weapon. It is also common to find American combat medics who are no longer wearing the red or white cross because it is considered unethical to do so when the combat medic is carrying a weapon and could engage in actual combat. In the U.S. Navy, enlisted medical personnel are known as corpsmen, not medics. The colloquial form of address for a Hospital Corpsman and Army Medics is "Doc". In the Army and U.S. Marine Corps,