Suppressive fire is a tactic to reduce casualties to friendly forces and enable them to conduct their immediate mission. For example, a suppressed target will be unable to engage vulnerable forces that are moving without cover. This enables forces to advance to new positions or to close with the enemy. For example, a US Marines article notes that "communication and suppressive fire are what enables movement on the battlefield, giving Marines the upper hand." Suppressive fire may be used to enable a helicopter or boat to land or extract soldiers from a battle zone (the latter is called a "hot extraction").