New Delhi, May 21 -- U.S. Marines test fired a dozen rockets from a mobile launcher on Wednesday at a range in the foothills of Japan's iconic Mount Fuji, in an exercise to keep sharp on weapon that is a growingly important component of the American military's arsenal.

The High Mobility Artillery Rocket System (HIMARS) is a launcher mounted on the back of a military truck that can be rapidly brought out from concealment, fire its rockets, then move quickly to a new location to avoid counter-battery fire. The so-called "shoot and scoot" tactics are becoming increasingly important with the proliferation of drones over the battlefield, which make static positions more vulnerable.

The system has been used by U.S. forces in Iraq and Afghanis...