According to reports, the U.S. Defense Intelligence Agency (DIA), in its 2025 Worldwide Threat Assessment, states: “Russia is expanding its nuclear forces by adding new capabilities, including nuclear air-to-air missiles and novel nuclear systems.”
The report has stirred considerable speculation and debate. The War Zone, for example, in an article headlined “Russia Fielding New Nuclear-Armed Air-To-Air Missiles: U.S. Intel”, states: “Russia is introducing new nuclear-tipped air-to-air missiles as part of an overall expansion of its nuclear forces.”
Continuing its analysis, it adds: “Since this is described as a new weapon, it’s almost certainly a reference to a version of the R-37M, a very long-range air-to-air missile.”
However, as quoted by Flight Global, the DIA report does not refer to a specific new weapon. It mentions new capabilities, without naming or describing any particular missile.
It’s possible that the DIA report alludes to the operationalization of an existing capability rather than the deployment of a new missile.
Hyping Russian military developments as evidence of aggressive intent has become common in some sections of the Western media.
August 2024 Nuclear Exercise
In August 2024, the Russian Ministry of Defense (RuMoD) released footage showing MiG-31BM interceptors being armed with long-range air-to-air missiles during the third phase of a non-strategic nuclear weapons exercise.
The footage, part of a training exercise involving the deployment and potential use of tactical nuclear weapons, hinted that the missile in question might be nuclear-capable.
The missile shown being loaded was identified as the R-33 (NATO designation: AA-9 Amos), which can intercept a range of aerial targets—including low-flying cruise missiles—at speeds up to 3,000 km/h.
R-33 Missile
First deployed in 1981, the R-33 featured a combination of inertial guidance and SARH (Semi-Active Radar Homing), with an operational range of approximately 120 km. The Soviet Union developed it primarily to engage large, fast targets such as the SR-71 Blackbird, the B-1 Lancer, and the B-52 Stratofortress.
Armed with the R-33, the MiG-31BM could engage U.S. bombers while remaining outside the engagement range of escort fighters like the F-15 Eagle. In the early 1980s, the F-15 carried missiles with ranges under 100 km.
A later variant, the R-33S, was equipped with an active radar homing warhead.
Zaslon Radar
The R-33 was designed to exploit the MiG-31BM’s Zaslon phased-array radar, a technological milestone as the first Passive Electronically Scanned Array (PESA) radar deployed on a fighter aircraft.
Until then, PESA systems had only been mounted on ground installations or strategic bombers like the B-1.
A long-range missile required a radar with long-range detection. The Zaslon could detect a 16 sq. m target at a distance of 200 km. It also offered “look-down, shoot-down” capability, enabling the MiG-31 to target low-flying cruise missiles. The radar could guide up to six missiles simultaneously at separate targets.
Nuclear Warhead?
In the 1950s and 1960s, nuclear-tipped air-to-air missiles were seen as an effective way to destroy bomber formations. Both the U.S. and the Soviet Union developed such weapons.
Some Soviet-era air-to-air missiles were designed with dual conventional and nuclear warhead capabilities in line with Cold War doctrines. However, Russia has never officially confirmed the existence of nuclear warheads for air-to-air missiles.
The U.S. Air Force also developed nuclear-capable air-to-air missiles such as the AIR-2 Genie and the AIM-26 Falcon:
The AIR-2 Genie was an unguided nuclear rocket intended to destroy entire bomber formations with a single blast.
The AIM-26 Falcon was a guided missile with either a nuclear or conventional warhead and was the only U.S. air-to-air missile with both nuclear capability and semi-active radar homing.
It is likely that the R-33 was nuclear-capable but never actually fitted with a nuclear warhead. As the missile’s range and accuracy improved, the need for a nuclear payload may have diminished.
R-33 Upgrades
Since entering service, the R-33 has undergone major upgrades. The version deployed on MiG-31s since 2012 reportedly has a range exceeding 300 km. Targeting systems have also improved, significantly enhancing strike precision.
With speeds of up to Mach 6, the missile is difficult to evade, even for high-performance fighter aircraft at extended ranges.
The missile remains relevant today. U.S. fighters like the F-35 and F-22 Raptor have air-to-air missile engagement ranges of around 130 km and 105 km, respectively, giving the MiG-31BM a clear BVR (Beyond Visual Range) advantage.
R-37
Russia developed the R-37 as the successor to the R-33. Its export variant is known as the RVV-BD. The R-37 uses a dual-pulse rocket motor, making it highly energetic and maneuverable during terminal engagement.
Some reports claim the missile can engage targets at ranges up to 400 km.
Unlike the R-33, the R-37 has been integrated into a broader range of platforms, including the Su-57, Su-35S, and Su-30SM.
However, the R-33 remains exclusive to the MiG-31BM.
Change In Role
The release of footage showing the R-33 being used in a nuclear exercise was likely a deliberate message: Russia has now assigned the R-33 a tactical nuclear role. The DIA report may simply reflect acknowledgment of that message.
Why Russia would equip the R-33 with a nuclear warhead is not entirely clear.
One possibility is the perceived threat from the B-21 Raider stealth bomber. Its all-aspect stealth may prevent effective radar lock-on for conventional terminal homing. The R-37, in its current form, might be ineffective against such a target.
Russia likely views the B-21 as a major threat due to its ability to penetrate high-threat environments independently, and its potential to operate alongside unmanned systems or control drone swarms in future warfare.
Conclusion
Russia has likely assigned a nuclear role to the R-33 air-to-air missile—first fielded in the 1980s—as a response to evolving threats such as the B-21 stealth bomber, which may be immune to conventional interception methods.
This shift represents a doctrinal and tactical adaptation to the next generation of stealth threats.
- Vijainder K Thakur is a retired IAF Jaguar pilot, author, software architect, entrepreneur, and military analyst.
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