Radio made possible a unique military unit, the LRRP (Long Range Reconnaissance Patrol.) With a radio, a small unit of men could (if skillful enough) sneak deep into enemy territory and report back what they found. Starting in World War II, numerous LRRP units were formed for this kind of dangerous work. In the United States Army, LRRPs went in and out of fashion depending on whether or not there was a war on. Some LRRP units were formed during World War II, and then disbanded after the war. Same thing during the Korean war, although two LRRP companies were created in 1958 for missions deep into Russian controlled territory. LRRPs sprang up spontaneously in Vietnam. All but two companies were disbanded after the war, and these two companies were used in 1974 to form the Ranger Regiment. But in the early 1980s, as the U.S. Army got serious about troop quality and training, the need for LRRPs was felt once more. This time, the drill was a little different. The units were called LRSU (Long Range Surveillance Units) and generally operate in four man (rather than the 8-12 man LRRP) units. Better equipment and the ability to send the patrols deeper made smaller units more effective. LRSU are expected to stay out there for up to 30 days at a time. LRSUs have been used in every American conflict in the last two decades. LRSUs have also been used in anti-drug and anti-terrorist operations. While still trained to fight, the long range scouts are given even more intensive instruction on staying hidden. Being a LRSU is considered on a par with Rangers or Special Forces, if only because LRSU will often go into an area before any of those other elite troops.