Mobility is regarded as a vital component of the modern battlefield, as the ability to deliver weapon systems or combat units to their objective quickly can often mean the difference between victory and defeat.
In the face of overwhelming firepower presented by machine guns and artillery, that resulted in stalemate and an inability to outmaneuver the enemy.
By World War II, battlefield mobility had greatly improved with the development of the tank, and with tracked and other mechanized vehicles, to move forces to, from, along and across the battlefront even under fire.
By the 1980s, for example, intercontinental travel shifted from sea to air transport, enabling military forces to move from one part of the world to another within hours or days instead of weeks.
In 2016, Chief of Staff of the United States Army Gen. Mark A. Milley stated that "On the future battlefield, if you stay in one place longer than two or three hours, you will be dead... With enemy drones and sensors constantly on the hunt for targets, there won't even be time for four hours' unbroken sleep".