Russian incursions into U.S. air identification zones have increased in the past year. Here, two U.S. Air Force F-22 fighters appear visible in this video screen grab shot from a Russian Tu-95MS bomber as it approached Alaska, Oct. 19, 2020. Russian Federation Ministry of Defense
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Forging a SHIELD for the Homeland

Jan. 25, 2021

A ‘new era’ of domestic air defense dawns.

A pair of F-22s scrambled into the arctic sky Oct. 19, in hot pursuit of two Russian bombers that had just penetrated the Alaskan Air Defense Identification Zone. It was, the 14th such incursion of 2020—a potentially record-setting, post-Cold War pace. It also highlighted growing concern among U.S. and Canadian commanders over domestic air defense. 

The Tu-95 bombers, escorted by two Su-35 fighters and supported by an A-50 airborne early warning aircraft, were merely testing U.S. and Canadian responses, executing a dry run for a notional conventional strike on critical infrastructure in order to impair U.S. power-projection capabilities. 

“The strategic threat to the homeland has entered a new era,” Air Force Gen. Terrence J.  O’Shaughnessy warned Congress before he retired last summer, in the sharpest terms of his tenure as the dual-hatted head of U.S. Northern Command and the bi-national North American Aerospace Defense Command (NORAD).

The strategic threat to the homeland has entered a new era.Gen. Terrence O’Shaughnessy, then-dual hatted head of USNORTHCOM and NORAD

Russia and China, he said, have a range of new capabilities to hold the U.S. and Canada at risk with more than just nuclear strike options, including advanced long-range cruise missiles, maneuvering hypersonic strike weapons and cyber attacks to offset U.S. military power-projection advantages, and limiting U.S. diplomatic options in a crisis.

Such a prospect has prompted a rethink over the last year at the highest levels of the Pentagon about the need for a robust domestic air defense capability to protect the entire nation—which has long relied on two vast oceans and airborne defense against adversaries attacking the continental United States. 

In the future, more will be needed, warned Mike Griffin, then Pentagon chief technology officer in an October 2019 memo. “Increasing adversarial capability and capacity challenge the United States to provide homeland air defense for our nation,” Griffin wrote. “Proliferation of enemy weapon systems with global reach dictate that the United States can no longer presume domestic sanctuary.”

Griffin, who departed the Pentagon in July, directed the influential Defense Science Board to dig into the matter. The panel’s classified work is not yet complete, according to a spokesman, but a senior Air Force official said its early findings are already shaping plans, budgets, and modernization strategies at NORAD, specifically its new construct for domestic air defense.


Growing Russian and Chinese threats—specifically new long-range, conventional strike weapons designed to hobble critical domestic infrastructure—have NORAD seeking unprecedented air and maritime sensing capabilities, linked to joint all-domain command and control tools to guide a new array of anti-missile systems.

NORAD’s Strategic Homeland Integrated Ecosystems for Layered Defense (SHIELD) aims to harden maritime and air approaches to the United States to create a more capable, credible deterrent and complicate attempts to thwart U.S. force projection by attacking American airfields, ports, utilities, and economic significance.

“Our approach in the past has been to fight over there so that they don’t attack us here,” Air Force Brig. Gen. Pete M. Fesler, NORAD’s deputy director of operations, said in an interview. “Our adversaries recognize that, and they specifically developed methods to avoid our fielded forces and attack us in the homeland. So, this is no longer a choice of what type of fight we’re going to fight; our adversaries have made that decision for us. So we have to defend along the whole continuum from all the way forward in the other theaters to all the way back here where forces originate.”

The Advanced Battle Management System On-ramp 2 exercise in August 2020 tested the agility of an interconnected battle network. Here, Jason Davis, a cyber technician, monitors a live feed from inside a production truck as part of the exercise. Senior Airman Daniel Hernandez

SHIELD builds on nearly two decades of work on Homeland Defense Design, a NORAD project launched in the wake of the Sept. 11, 2001, terrorist attacks that aimed to improve the U.S. military’s ability to find, fix, track, target, and engage growing air threats, such as those posed by cruise missiles, low-slow aircraft, and long-range aviation.

Homeland Defense Design was used to forge new air defense packages for the National Capital Region, with an original goal to scale that capability and replicate it across the nation to defend locations deemed critical.

However, plans to proliferate around the nation Homeland Defense Design Block 3 air defense capabilities were canceled because the cost of the sensors and guided missile systems needed to protect the national capital was too great to expand that to defend the rest of the country. Instead, NORAD is now proposing that SHIELD can provide a new conceptual backbone for future domestic air defense modernization.

Fesler said the need is urgent. Russia and China are exploiting seams in U.S. and Canadian domestic defenses, including sensor networks that detect approaching threats as well as the allies’ ability to coordinate command and control across their many disparate systems.

The new SHIELD strategy calls for improving air defenses through a combination of existing and new equipment in combination with new technologies across three areas: domain awareness, join all-domain command and control, and defeat mechanisms.

NORAD is keeping many details of the specific technologies that would constitute SHIELD under wraps. “As you can imagine, a lot of the stuff that we have, we talk about—specific capabilities and specific programs—immediately gets into the classified realm,” Fesler noted.

Still, he outlined the contours of the new concept and other senior leaders in various forums over the last year have pointed to new capabilities that are slated to be part of SHIELD.

Domain Awareness

The SHIELD vision for homeland domain awareness calls for sensors—originally designed to provide information in a unique format to a designated platform—to instead feed data to a central repository where it is then available for access by all users across the enterprise.

“What SHIELD does differently than our previous approaches is really focused on not a single threat, but a range of threats,” said Fesler. “When I say multiple threats for a single sensor, that’s not to suggest we want to buy one gold-plated system that can do all things for all people. Rather, it’s the layering part of that, that really makes this unique. It’s a combination of using things like old systems that are being repurposed from their original design spec to give us data. It’s taking old technology and then using it not only in creative ways, but putting [new] computers on the back end of it, they help us pull more [data] out of those old systems. And in some cases, it’s the purchase of new systems and fill gaps that aren’t covered by any of those other things. That’s not the approach we’ve taken in the past. And I think that’s what’s maybe a little bit revolutionary rather than evolutionary when we look at SHIELD.”

A pilot project paired new computer processors with legacy Federal Aviation Administration (FAA) radars and proved able to detect and track very small unmanned aircraft without any modifications to the sensors.

Mike Tsukamoto/staff

“One of the things that we’re finding particularly interesting is its ability to breathe new life into existing sensors by putting better processing power behind the sensors that already are out there,” Fesler said. “You can imagine what the computers looked like if they’re attached to a radar that was built in 1985. Now take modern computer processing and put it against that same radar. You get a pretty significant increase in capability.”


DOD’s recent adoption of joint all-domain command and control as a collective, joint-service goal is critical to NORAD’s strategy. JADC2 technologies will be needed to tie together independent systems and then direct the best possible response, be it from the Air Force or Space Force, or the Army, Navy, Marines, Coast Guard, or Canadian forces.

The first two in a series of Air Force Advanced Battle Management System on-ramp events were conducted with NORTHCOM. The events focused on defending against cruise- missile attacks on U.S. territory. Fesler said both events aimed to showcase an ability to detect, track, and identify incoming weapons and then hand those tracks to a fire unit to destroy the incoming cruise missile.

“One of the things that we learned is, in order to enable that, you really need that robust command and control system that we talk about in SHIELD,” according to Fesler.

Defeat Mechanisms

The third element of the SHIELD strategy deals with “defeat mechanisms” to blunt an attack. NORAD relies on weapon systems optimized for deployment overseas and capable of working in rugged environments, features that add cost. The SHIELD strategy seeks ways to reduce costs by optimizing for defense of domestic locations.

Patriot surface-to-air missile defense systems, for example, were originally designed to protect Army units while on the move. They’re built to travel over rough terrain and hardened to operate through chemical or biological attacks. NORAD believes it can cut costs by stripping out some of those features while retaining its advanced fire-control system. 

In addition, SHIELD calls for adopting new, nonkinetic technologies, such as high-powered lasers and microwave weapons.

NORAD’s current Integrated Air Defense System (IADS)deployed in the National Capital Region—featuring the National Advanced Surface-to-Air Missile System that utilizes an AIM-120 interceptor and its expeditionary system, the Deployable-IADS (D-IADS)—is an Avenger short-range air defense system.

Canadian Buy-In?

In the past, the U.S. and Canada have not seen eye-to-eye on missile defense policy, which is one reason ballistic missile defense of the U.S. homeland is the domain of U.S. Northern Command, not NORAD. As SHIELD works to integrate guided missile interceptors or directed-energy weapons into the air-defense equation, the kinetic dimension could raise thorny issues for the two nations.

“If this works, it will be a great step forward,” said Christopher Sands, director of the Wilson Center’s Canada Institute. “If it generates the kind of pushback that it might from Canada, we will have to retool it to see if we can figure out a way to make something like this work.”

NORAD has adopted a plan to implement SHIELD over time, using “spiral“ improvements. The first step calls for repurposing and integrating existing sensors. The second calls for using data analytics with existing sensors, applying the Pathfinder pilot program to FAA and NAV CANADA (Canada’s civil air navigation service) radar feeds.

New Sensors

The third SHIELD spiral calls for fielding new sensors.

In January, the Air Force completed installation of new Northrop Grumman AN/APG-83 SABR radars on F-16s operated by the Air National Guard at Joint Base Andrews, Md. That project directly supports a NORAD Joint Emergent Operational Need to improve National Capital Region defenses against cruise missile threats. In February, the Air Force urged Congress to support fiscal 2021 funding for an additional 150 new radars for the F-16 fleet: “This program directly maps to the [National Defense Strategy] as it provides the most critical upgrade to the F-16’s ability to successfully defend the homeland against attack,” the Air Force said.

NORAD recently added a new wide-area surveillance system to provide overwatch of the National Capital Region consisting of the Stateside Affordable Radar System and Scorpion to detect and track low, slow, and related asymmetrical threats in and around Washington, D.C., airspace.

To provide point defense of other “critical“ sites—whether domestic military posts, urban areas, or other “nodes” such as computer server farms, power stations, or transportation hubs—NORAD is now looking for new over-the-horizon radars to improve detecting cruise-missile and hypersonic threats.

The National Advanced Surface-to-Air Missile System is a highly adaptable mid-range, air defense system integrated into the U.S. Capital Region’s air defense toolbox in 2005. Raytheon

The Missile Defense Agency (MDA), in direct support of NORAD and NORTHCOM, earlier this year established a new Cruise Missile Defense-Homeland architecture organization to explore folding in a new layer to the Ballistic Missile Defense System dedicated to these air-breathing threats. This organization is working with the Office of the Secretary of Defense and the Naval Surface Warfare Center, Crane Division in Indiana to assess an elevated electronically scanned array radar called Sentry that NORAD sees as having potential for mid-range detection. This sensor, one of a few elevated sensor options being assessed, would be used to detect and track targets with low-radar cross sections, such as cruise missiles and unmanned aircraft.

Other technologies being assessed include wide-area persistent surveillance systems, 360-degree-coverage fire-control sensors, command and control and battle management alternatives, and different defeat mechanisms, according to a Pentagon official.

Separately, Air Combat Command this fall was finalizing the Northern Approaches Surveillance Analysis of Alternatives (NAS AoA), a bi-national study with Canada’s Department of National Defence—a project that aims to identify ways to improve NORAD’s ability to counter airborne threats across vast geographic areas.

“The final NAS AoA report is being drafted and is expected to be reviewed by Air Force leaders this fall,” said ACC spokeswoman Leah Garton. This study aims to present alternatives that reduce the life-cycle cost of legacy sensors for the U.S.-Canada North Warning System, while also enhancing air surveillance capabilities in the Arctic region, she added.

ders on costs, capabilities, and potential material solutions “for the modernization of persistent, long-range, wide-area air surveillance in the northern approaches to North America,” she said. The Air Force is eyeing fiscal 2023 to proceed with potential material solutions, and is forecasting a 10-year window beginning in FY25 to adopt new technologies and capabilities, while considering requirements beyond 2035.

Meantime, House lawmakers—in their version of the fiscal 2021 defense policy bill—recommended that MDA and NORTHCOM prepare a report on cruise-missile defense to identify “any vulnerability of the contiguous United States to known cruise-missile threats” and develop “a plan to mitigate any such vulnerability.”

What Cost?

NORAD has no authority to independently procure new weapons technology, so the command is reliant on persuading U.S. and Canadian defense officials to fund the SHIELD strategy.

NORAD officials declined to share cost estimates.

Instead, NORAD spokesman Bill Lewis, said “through the development of a purpose-built homeland defense capability, we actually reduce the demand for the forces provided by the services. … SHIELD capitalizes extensively on existing capabilities, eliminating the need for an entirely new architecture.”

Russian Tu-95 bombers, shown here with wing-mounted Kh-101 cruise missiles at Engels Air Base, Saratov, Russia, probed U.S. and Canadian air spaces to see how they’d respond in October, the 14th such provocation of 2020. Russian Federation Ministry of Defense

Fesler said he expects the Pentagon and Congress to support the effort.

“A lot of it is going to depend on what we actually buy and when the phasing is,” he said. “What I can tell you, though, is that the defense of the homeland is affordable. And it’s necessary. I don’t think there are very many people that would say, ‘Yeah, we just can’t afford to defend ourselves.’”

Operation Noble Eagle

All these new technologies are designed to improve operations in U.S. and Canadian airspace that are rolled up in the 24/7/365 mission called Operation Noble Eagle, executing NORAD’s primary task: surveillance and control of North American airspace.

This operational mission, supported by about 200 exercises annually, aims to respond “rapidly and appropriately” to potential threats, using a graduated response culminating in the use of lethal force, if necessary.

Since resuming long-range bomber flights within North American striking range in 2007, Russia had triggered an average of six or seven NORAD scrambles a year—through 2019. But in 2020, Russia increased its sorties dramatically.

In September, NORAD declassified reports for the first time indicating that Russian approaches to North America peaked in 2014 at 15 missions. So, in October, when the two F-22s—supported by a KC-135 tanker and AWACS—intercepted the Russian bombers in international air space near the Alaskan shore, it marked a 14th, and a pace that left time for a new high to be set.

“During the Cold War, the Russians were very predictable,” said Steven Armstrong, NORAD vice director of operations. “If they wanted to launch some kind of attack against us in the air domain, specifically with their bomber aircraft, they had to fly to specific locations or points to be able to launch cruise missiles. And as we’ve seen over the last several years, in the last decade, specifically—like us, they have been able to update their weapon systems—so they don’t have to be as predictable. … So now, they can take off and with their equivalent of a global positioning satellite system, they can go to a point in space and they can now actually launch weapons from their airspace and hit our assets in either Canada or Alaska and in some cases down in the lower 48.”

Russia’s new AS-23 cruise missile and the modular KALIBR-NK cruise missile system and its precise land-attack capabilities are of particular concern.

“The homeland is no longer a sanctuary,” said Armstrong. The Atlantic, Pacific, and Arctic oceans no longer provide the same buffer they used to. “All of that space between us and potential enemy combatants: it [once] took them time, it took them significant capability to get to our shores. That is no longer the case with some of the weapons systems that are being developed and capabilities that are out there. Now, we have to change our paradigm: We have got to be able to protect from a distance, not just as they come to us.”

Jason Sherman is a senior correspondent for Inside Defense. His last article for Air Force Magazine, “The Arctic Heats Up,” appeared in the January 2018.