Russian President Vladimir Putin ignited fears of a potential World War 3 with the announcement that the world's most lethal nuclear missile was undergoing active testing seven years ago, yet reactions have been varied since then.

The RS-28 Sarmat missile, better known as Satan II, was heralded as the pinnacle of "next generation" warfare technology when Putin addressed the nation in 2018. Boasting unrivalled capabilities, it is said to be unmatched globally, with the power to deliver nuclear warheads to any location worldwide, posing a considerable threat to leading powers such as the US, the UK, and Europe.

Putin infamously declared this formidable addition to Russia's military inventory would cause other nations to "think twice" before challenging Russia. In stark contrast, the Pentagon swiftly countered by stressing that the missile does not pose a danger to the United States or its allies – but what underpins this confident assertion?

In terms of sheer scale, the weapon exudes menace: the missile measures an imposing 116 feet in length and tips the scales at a hefty 220 tons. It further impresses with an estimated range spanning 10,000 to 18,000km, significantly eclipsing Russia's previous intercontinental ballistic missile, the Voevoda (R-36).

According to local media outlets, the RS-28 may house as many as 16 independently targetable nuclear warheads, although speculations suggest the actual count may be closer to 'up to 10 warheads', reports the Mirror US.

The Sarmat missile, also known as Satan II, made headlines with its inaugural test flight on April 20, 2022. The Russian Defence Ministry announced: "At 15:12 Moscow time at the Plesetsk state test cosmodrome in the Arkhangelsk region, a Sarmat fixed-based intercontinental ballistic missile was successfully launched from a silo launcher."

Following this test, Russia revealed plans to have 50 new Sarmat missiles combat-ready soon.

However, doubts about the missile's reliability surfaced when, in February 2023, it reportedly created a large crater at the Plesetsk launch site in northern Russia, marking what some experts believe to be its fourth failure, casting serious doubts over the nuclear weapon's capabilities.

Matt Korda, an associate senior researcher at the Stockholm International Peace Research Institute (SIPRI), discussed the significance of the Satan II missile with Euronews Next. He described it as "politically significant" for Putin and noted that despite its setbacks, "construction continues."

Korda explained: "Russia has long planned to replace every single one of its Cold War-era delivery systems with newer versions," adding, "The RS-20V Voevoda is the last of these types of ICBMs left in its arsenal. As a result, the introduction of the Sarmat will be politically significant for President Putin, as the embodiment of Russia's completion of this long-awaited transition".

He further mentioned that despite Russian claims, the new RS-28 missile has not yet entered service, leaving its status somewhat ambiguous.

He said: "Not only has serial production of the missile been delayed, but its testing cycle has been marred by a series of postponed and failed tests. It is clear that Russia is proceeding with construction to facilitate the missile's deployment - satellite imagery indicates that major construction is well underway at the first regiment of the 62nd Missile Division in south Siberia, and will soon begin at other expected deployment sites."

Malcolm Chalmers, Deputy Director-General of the Royal United Services Institute (RUSI), highlighted Russia's position as the owner of the world's largest nuclear arsenal, boasting "already considerable destructive potential". Nevertheless, he argued the new Russian rocket contributes minimally to any existing threat.

Speaking to the Telegraph, he said: "Russia and the Western nuclear states have had the ability to annihilate each other ever since they acquired strategic nuclear bombers, followed by intercontinental ballistic missiles, over 60 years ago. Putin adding this new missile to his pre-existing 'overkill' capability makes absolutely no difference to the effectiveness of our Trident nuclear deterrent submarines."

As per the Arms Control Association, Russia possesses 6,257 nuclear warheads, totalling approximately half of the global count, which stands around 13,080. In contrast, the US, who plans to commence a $100 billion upgrade on its LGM-35A Sentinel intercontinental ballistic missile starting in 2029, reportedly has a stockpile of 5,550.

In third place, China is said to maintain an arsenal of 350 warheads.