or degree, as financial and national interests often overlap, and most standing regular armies also provide their soldiers with some form of payment. Furthermore, as reflected in the Geneva Convention, mercenaries are generally provided less protection under the rules of war than non-mercenaries, and many countries have criminalized "mercenary activity". Intense debates can build up over which term is to be used to refer to a specific group. Using one term over another can strongly imply strong support or opposition for the cause. It is possible for a military to cross the line between regular and irregular. Isolated regular army units that are forced to operate without regular support for long periods of time can degrade into irregulars. As an irregular military becomes more successful, it may transition away from irregular, even to the point of becoming the new regular army if it wins. Regular military units that use irregular military tactics Most conventional military officers and militaries are wary of using irregular military forces and see them as unreliable, of doubtful military usefulness, and prone to committing atrocities leading to retaliation in kind. Usually, such forces are raised outside the regular military like the British SOE during World War II and, more recently, the CIA's Special Activities Division. However at times, such as out of desperation, conventional militaries will resort to guerilla tactics, usually to buy breathing space and time for themselves by tying up enemy forces to threaten their line of communications and rear areas, such as the 43rd Battalion Virginia Cavalry and the Chindits. Although they are part of a regular army, United States Special Forces are trained in missions such as implementing irregular military tactics. However, outside the United States, the term special forces does not generally imply a force that is trained to fight as guerillas and insurgents. Originally, the United States Special Forces were created to serve as a cadre around which stay-behind resistance forces could be built in the event of a communist victory in Europe or elsewhere. The United States Special Forces and the CIA's Special Activities Division can trace their lineage to the OSS operators of World War II, which were tasked with inspiring, training, arming and leading resistance movements in German-occupied Europe and Japanese occupied Asia. In Finland, well-trained light infantry Sissi troops use irregular tactics such as reconnaissance, sabotage and guerrilla warfare behind enemy lines. The founder of the