Since the dawn of modern warfare, the best way to stay alive in the face of incoming fire has been to take cover behind a wall. But thanks to a game-changing "revolutionary" rifle, the U.S. Army has made that tactic dead on arrival. Now the enemy can run, but he can't hide.

After years of development, the U.S. Army has unleashed a new weapon in Afghanistan -- the XM25 Counter Defilade Target Engagement System, a high-tech rifle that can be programmed so that its 25-mm. ammunition detonates either in front of or behind a target, meaning it can be fired just above a wall before it explodes and kills the enemy.

It also has a range of roughly 2,300 feet -- nearly the length of eight football fields -- making it possible to fire at targets well past the range of the rifles and carbines that most soldiers carry today.

Lt. Col. Christopher Lehner, project manager for the semi-automatic, shoulder-fired weapon system for the U.S. Army's Program Executive Office Soldier, said that the XM25's capability alone is such a "game-changer" that it'll lead to new ways of fighting on the battlefield, beginning this month in Afghanistan.

"With this weapon system, we take away cover from [enemy targets] forever," Lehner told FoxNews.com on Wednesday. "Tactics are going to have to be rewritten. The only thing we can see [enemies] being able to do is run away."

And that would make it much easier for U.S. troops to put them in their sights, either with that same XM25 or another direct-fire weapon.

With this new weapon in the Army's arsenal, Lehner said, "We're much more effective, by many magnitudes, than current weapons at the squad level. We're able to shoot farther and more accurately, and our soldiers can stay behind sandbags, walls or rocks, which provides them protection from fire."

Lehner said the first XM25s were distributed to combat units in Afghanistan this month. The 12-pound, 29-inch system, which was designed by Minnesota's Alliant Techsystems, costs up to $35,000 per unit and, while highly sophisticated, is so easy to use that soldiers become proficient within minutes.

"That's how intuitively easy it is, even though it's high-tech," Lehner said. "All a soldier needs to know how to do is laze the target. It decimates anything within its lethal radius."

Once the trigger is pulled and the round leaves the barrel, a computer chip inside the projectile communicates exactly how far it has traveled, allowing for precise detonation behind or ahead of any target.

"We have found that this has really made our soldiers so much more accurate and being able to deliver this high-explosive round in about five seconds," said Lehner, taking into account the time it takes a soldier to laze, aim and fire the weapon. Once fired, Lehner said, the round will reach its target in a "second or two," meaning the entire process from aiming to direct hit lasts less than 10 seconds, compared to 10 minutes or longer for traditional mortar fire.

A potential battlefield scenario, according to Army officials, might go something like this:

-- A patrol encounters an enemy combatant in a walled Afghan village who fires an AK-47 intermittently from behind cover, exposing himself only for a brief second to fire.

-- The patrol's leader calls for the XM25 gunman, who uses the weapon's laser range finder to calculate the distance to the target.

-- He then uses an incremental button located near the trigger to add 1 meter to the round's distance, since the enemy is hiding behind a wall.

-- The round is fired, and it explodes with a blast comparable to a hand grenade past the wall and above the enemy.

"This is revolutionary for many reasons," Lehner said, citing increased efficiency, safety and lethality. "This is the first time we're putting smart technology in an individual weapon system for our soldiers. We feel it's very important to field this because it keeps us ahead of the technological curve of our potential enemies. We have a feeling other people will try to copy us -- this is the future."

Lehner said the Army plans to purchase at least 12,500 XM25 systems beginning next year -- enough for one system in each infantry squad and Special Forces team.

The military isn't overly concerned that the weapon might be captured by the enemy, because they would be unable to obtain its highly specialized ammunition, batteries and other components. Lehner said he expects other nations will try to copy its technology, but it will be very cost-prohibitive.

"This is a game-changer," Lehner said. "The enemy has learned to get cover, for hundreds if not thousands of years.

"Well, they can't do that anymore. We're taking that cover from them and there's only two outcomes: We're going to get you behind that cover or force you to flee. So no matter what, we gotcha."