The Army is equipping tanks with a high-tech protective system its been working on for decades as it prepares for potential great-power war

US Air Force

• After decades of research, the Army has decided to do a wide roll-out of active-protection systems for Abrams tanks.
• APS are designed to thwart incoming antitank missiles and other projectiles.
• Such defenses have renewed relevance for the Pentagon, which is refocusing on potential large-scale conflict.

The US military has made clear its renewed focus on adapting to the "reemergence of long-term, strategic competition" with powerful state actors, most notably Russia and China, that was outlined in the Pentagon's National Defense Strategy earlier this year.

The release of the Defense Department's 2019 budget proposal detailed some of the specifics of those preparations, and the Army appears to have settled on a long-awaited upgrade for its main battle tank.

The budget for the coming fiscal year will equip 261 M1 tanks, three brigades' worth, with Israeli-made Trophy active-protection systems, according to Breaking Defense.

Active-protection systems are designed to fend off antitank missiles and other incoming projectiles. The Trophy system, called Windbreaker, uses four mounted antennas, which offer 360-degree coverage, and fire-control radars to pick up incoming targets. Internal computers then devise firing angles and signal two rotating launchers on the sides of the vehicle to fire ball-bearing-filled canisters. The system has been installed on Israel's Merkava main battle tanks since 2009.

Congressional Research Service

How an APS works.

"If you look at what we've done in the last 15 years, it is a light, aviation-centric fight, so we took a fair amount of risk on the heavy force," John Daniels, deputy assistant secretary of the Army for Plans, Programs, and Resources, told Breaking Defense.

"Now you are at a point where the system is starting to age out," Daniels said. "If you look at the ages of platforms and how long it takes to rebuild a heavy brigade, you (need to modernize) about one, 1.5 a year to really make a substantive change." He added the pace of those upgrades would depend on decisions made in 2019 and 2020.

The 2019 budget proposal requests $182.1 billion for the Army - $5.6 billion would go to weapons and tracked-combat-vehicle procurement. The Trophy system is estimated to cost $350,000 to $500,000 for each tank.

US Marine Corps

A sailor guides a Marine driving an M1A1 Abrams Tank from the deck of a landing craft to Camp Pendleton's White Beach.

US military officials have said the Abrams remains at the top of its class, but they've also warned that foreign militaries are gaining on it. Other militaries have looked to add their own APS and boost their antitank capabilities to counter adversaries' versions of the systems.

The US has been looking at APS to protect armor for some time, lingering in the design and development stages since the 1950s. In 2016 and 2017, the Army leased and purchased some Trophy systems for testing.

APS has grown in relevance amid ongoing tensions with Russia, which maintains a large tank force - some with their own APS - as well as extensive anti-armor capabilities. The US military's interest in active-protection systems is not limited to Abrams tanks, however.

The Army is evaluating the Israeli-made Iron Fist APS for Bradley fighting vehicles and the US-made Iron Curtain APS for Stryker combat vehicles. Those programs are still in research and development, Pentagon officials told Breaking Defense, with decisions about procurement and funding yet to be made.

Lt. Gen. John Murray, deputy chief of staff, Army G-8, said late last year that the Abrams-mounted Trophy system was the farthest along in testing, but he noted at the time that safety concerns could be an issue, saying that firing and detonating APS projectiles near tanks could complicate coordinated operations between armor and dismounted infantry.

US Army Pfc. Victor Ayala

A US Army Stryker combat vehicle firing a TOW missile.

In addition to "hard kill" active-projection systems, which use physical countermeasures, the Army has said it is looking at "soft kill" APS, which would use countermeasures like electromagnetic signals to interfere with incoming threats.

Both would be a part of a Modular Active Protection System, which is "a framework for a modular, open-systems architecture" that would allow APS to function once installed. Col. Kevin Vanyo, program manager for Emerging Capabilities at the US Army Tank Automotive Research, Development, and Engineering Center, told the Army News Service late last year.

The Army has already started to take delivery of the latest version of the Abrams, receiving six M1A2 SEP v3 Abrams main battle tank pilot vehicles in October. Among its features were an upgraded radio system, enhanced power generation, and turret and hull armor upgrades.

"The Abrams M1A2 SEPv3 is the first in a series of new or significantly improved vehicles that we will be delivering to" Army armored combat brigade teams, Maj. Gen. David Bassett, program executive officer for Ground Combat Systems, said at the time. "It is a great step forward in reliability, sustainability, protection, and on-board power which positions the Abrams tank and our ABCTs for the future."

Under the fiscal year 2019 budget, $1.5 billion would go toward upgrading 135 M1A1 Abrams tanks to the M1A2 SEP v3, with delivery of the first six set for July 2020.