America’s New B-21 Stealth Bomber is Revolutionary: These Are Its Enemies’ Best Assets to Take It Down

The induction of the B-21 Raider intercontinental range strategic bomber into service in the U.S. Air Force in the late 2020s is expected to revolutionise the service’s strike capabilities, with the aircraft set to enjoy a production run of over a decade potentially beyond the 2030s should proposals for a fleet size of over 200 be realised. Although shorter ranged and less heavily armed than existing U.S. bomber classes, the B-21 is expected to have lower maintenance requirements, a higher sortie rate and far superior stealth capabilities. Where its predecessor the B-2 saw production cut to just 20 aircraft due to performance issues and extreme cost overruns, meaning the pressure a B-2 fleet could ever place on an adversary’s air defences was always limited, the size of the B-21 fleet potentially an order of magnitude greater is expected to pose very significant new challenges for adversaries across the world. The United States is expected to face a similar challenge, however, as China inducts its intercontinental range H-20 bomber into service at around the same time, albeit potentially in smaller numbers, which will place unprecedented strain on the defences of the American mainland supplementing that already placed by Russia’s older fleet of bombers. An assessment of a single asset fielded by each of America’s five leading potential adversaries that could potentially pose the greatest threat to the B-21 in the air is given below. Although all these assets would in all cases operate as part of a larger air defence network, their capabilities are here assessed in insolation. 

Russia S-500

While the B-21 saw delays of two years to its first flight, now scheduled for 2023, and could well see its service entry pushed back to the 2030s if trends from other American stealth programs serve as a precedent, Russia’s most capable asset capable of countering these aircraft saw delays significantly greater still and only entered service in 2021 over half a decade behind schedule. The S-500 is nevertheless an asset without peer in the world which was designed primarily for strategic level air defence, with an extremely powerful sensor suite allowing it to detect stealth aircraft at very long distances particularly when networked with aircraft and other air defence systems such as S-400s and Rezonans radar systems. The S-500 was designed to be capable of intercepting hypersonic targets including space aircraft, as well as strategic attacks from both bombers and intercontinental range ballistic missiles at extreme ranges. Although it almost certainly will be unable to use its full 600km engagement range against the B-21 due to the bomber’s stealth capabilities, the power of the S-500’s sensors particularly when operating as part of a network with widely dispersed long range radars in multiple bands will allow it to seriously threaten the bombers. Despite long delays in the program, S-500s are expected to be very widely deployed by the time the B-21 enters service and, due to delays in developing a new interceptor to succeed the current MiG-31, they will likely be the primary threat faced by the long range bombers should they seek to penetrate Russian airspace. S-500s are also expected to see deployments beyond Russian territory, with Algeria, China, India and Belarus being leading possible clients. Deployments to Russian bases in Belarus, and possibly in Syria, remain likely, as does the system’s integration onto future generations of destroyers should these ever be funded. 

China J-20

Although Chinese People’s Liberation Army deploys one of the most capable ground based air defence networks in the world, as the only country other than the United States to field an indigenously developed fifth generation fighter the capabilities of its combat jets are expected to pose the greatest threat to enemy bombers. Over 200 J-20 stealth fighters are currently thought to be in service, with the fleet likely being well over twice as large by the time the B-21 becomes operational and potentially four times as large by the time a sizeable B-21 fleet can be fielded. By that time both China and United States are expected to have furthered their leads over the rest of the world in fighter aviation and begun to field peerless sixth generation fighters which are currently well under development.

The J-20’s advanced network centric warfare capabilities and sensors, and its anticipated ability to operate alongside multiple classes of wingman drones many of them carrying sensors of their own, will potentially allow it to detect an engage B-21s at long ranges. The fact that China was the first country to widely deploy air to air missiles with AESA radars, with a lead in the sensors on its missiles expected to be maintained, poses further challenges for the B-21’s stealth capabilities not seen elsewhere in the world. China’s widespread deployment of KJ-500 airborne early warning aircraft alongside J-20 units, as well as the sharing of data with ground based air defences and with other fifth generation fighter classes, will ensure a very high degree of situational awareness unmatched among other U.S. adversaries.

North Korea Pyongae-6

Although unable to acquire fighter aircraft from abroad due to UN embargoes, North Korea has rapidly modernised its air defences since the mid 2010s with the induction of new systems with varying ranges. The most notable of these have been the Pyongae-5 which entered service in 2017 and its unnamed successor speculated to be called the Pyongae-6. The North Korean air defence network has long been one of the densest in the world, and as older S-75 and HQ-2 systems are replaced with the new 21st century assets the possibility of enemy penetration flights is expected to diminish significantly. First unveiled in October 2020, the Pyongae-5’s successor benefits from twin rudder control and a double-impulse flight engine and has been widely compared to the Russian S-400 system. The B-21 is particularly important to strikes on North Korea due to the vulnerability of airfields deploying tactical assets such as F-35s within range of the country, as North Korean strike capabilities have continued to advance rapidly. The aircraft’s ability to carry penetrative bombs such as the GBU-57 is also vital to allow the U.S. Air Force to destroy fortified positions, with North Korea considered the most heavily tunnelled country in the world and its military facilities including many production facilities located deep underground. The small size of North Korean territory and the density of fortified radar positions and highly mobile air defence assets makes it a particularly challenging target, with new long range air defence systems posing a primary challenge supplemented by that of very widely used handheld infrared guided anti aircraft assets. 

Iran: F-14 

Much like Russia and North Korea, Iran has relied very heavily on ground based air defence systems to compensate for the declining relative capabilities of its air force since the end of the Cold War. No single air defence system has particularly outstanding capabilities relative to others, however, with the Bavar 373, Khordad 15 and Russian-supplied S-300PMU-2 long range systems having broadly comparable capabilities and being widely deployed – albeit far less densely than air defence systems in North Korea have been. Iran deploys no airborne early warning aircraft and no fighter classes with active radar guided missiles, with the sole exception being its F-14 fighters than integrate very large radars and Fakour 90 missiles. The F-14 was designed primarily with combat against enemy bombers in mind, and while the B-21’s stealth capabilities will seriously limit the fighter’s ability to target it at long ranges the fighter still represents the preeminent threat of any single Iranian asset. The degree to which F-14s have been modernised to be able to network with ground based radars remains uncertain, but should they be able to share targeting data with systems such as S-300s and Rezonans-NE radars they could pose as significantly greater challenge – albeit one still limited by the fighter’s age. 

Belarus: S-400

As Belarus as strengthened its defence ties with Russia significantly since 2020 it has received growing quantities of advanced asymmetric weapons systems, with new S-400s strengthening its already very dense air defence network made up of Soviet era S-300 variants. As Belarus has only a single squadron of post Soviet fighter jets, namely recently delivered Su-30SMs which lack the anti stealth capabilities of the higher end Su-35, the S-400 will pose the most serious challenge to American B-21s in the event of war. Closer integration between the armed forces of Russia and Belarus mean that the air defence networks of the two countries will share targeting data, and that Belarusian S-400s could benefit from information from Russian aircraft with powerful radars such as MiG-31s and A-100 airborne early warning jets. The S-400 was designed to tackle older generations of stealth aircraft such as the B-2 bomber and F-22 fighter, although as the system has remained in production for close to two decades its capabilities have been steadily updated. Whether Belarusian S-500 acquisitions will materialise remains uncertain.