Russian President Vladimir Putin’s “special military operation” in Ukraine under the banner of what he calls “denazification” is clearly not going according to plan; and to believe or suggest otherwise is to systematically live in the bubble of modern-age disinformation.

The military campaign – which is supposed to last three days or so according to some US military officials and undoubtedly the Russian counterpart – now enters its fifth month. Far from abating, the fighting is still raging if not more intensifying. Some UK and US officials now say the conflict could continue for months or even years. Worse, some fear it might escalate into a nuclear confrontation.

Clearly, this isn’t the situation Russian leaders had envisioned and prepared for. On the contrary, it is exactly the scenario they had hoped to avoid. As they marshalled and stationed over 100,000 troops with massive columns of tanks, armoured personnel carriers, artilleries and self-propelled multiple rocket launchers along the border prior to the offensive, their calculation was that such a shock-and-awe display of force would break Ukrainians’ resolve to put up a fierce fight and that it would be over well before the EU and NATO countries had a chance to intervene to materially alter the course and the outcome of the offensive.

War hawks in Moscow couldn’t agree more with the assessment. Based on the Crimea experience which Russia annexed the Ukraine’s peninsula in 2014 with little resistance, it’s easy to argue that facing the world’s second most powerful military armed to the teeth at its border, Kyiv would in all probability choose appeasement and collaboration as opposed to tenacious resistance; and with Kyiv’s presumed acquiescence secured, there is effectively little reason or justification for EU and NATO to meddle in the conflict. Should they choose to do so, their efforts would be futile anyway without Kyiv’s willingness to go along.

As it turns out, that upbeat assessment proves acutely illusory. Russian leaders apparently miscalculated not only Ukrainians’ sheer patriotic sentiment and undaunted determination to fight, but also their combat readiness from top leadership to foot soldiers at the frontlines.

Moscow is now discovering the hard way that Ukraine has learnt the lessons of Crimea, and has since built up its military capability and has well prepared for the possibility of full-scale armed conflict with Russia. As noted on day one of Russia’s assault, Ukrainian President Volodymyr Zelenskyy promptly signed a general military mobilisation order barring all men aged 18-60 from leaving the country, effectively ensuring abundant manpower available to defend the country. Reportedly, he himself refused the US offer to evacuate, saying: “The fight is here; I need ammunition, not a ride.”

The West hears Zelenskyy’s pleas loud and clear and responds favourably with the speed not seen in recent memory. Within the next few frantic days following the Russian offensive, NATO and non-NATO EU countries alike swiftly start to pour in large military aids to Ukraine – setting the stage for the beginning of a potentially protracted armed conflict.

The freshly arrived military aid packages which include the RB 57 Next Generation Light Anti-tank Weapons (NLAW), the FGM-148 Javelins missiles and the Switchblade 300/600 drones have enabled Ukrainian forces to drastically paralyse and slow down the Russian ground troops to a crawl while inflicting heavy losses on them, both personnel and equipment. By mid May, Ukraine’s General Staff reported nearly 28,000 Russian soldiers had been killed since the start of the conflict.

In some respects, the fighting is more than just defending Ukraine’s sovereignty against Russia’s aggression. For NATO and especially the US European Command (USEUCOM), it’s an ideal occasion to demonstrate the lethality and effectiveness of their latest tank-killer arsenal against the powerful conventional tank warfare in European open terrain and urban environment; and perhaps more importantly, to reassess their own conventional armoured warfare doctrine and tactics in anticipation of the future proliferation of such high-impact-low-cost weaponry.

They also see it as a perfect moment to put to test their pan-European alliance’s cohesiveness and readiness; emergency crisis response measures; command, control and communications (C3) structure and interoperability; logistic and transport capabilities; and last but not least, real-time intelligence gathering and sharing.

For Russia, independent military analysts and veterans say the conduct of the military campaign so far couldn’t fare worse in numerous areas – from the military logistics, to the battlefield coordination and troops’ fighting morale, to the countermeasures against combat drones, to the vulnerability to enemy’s Signals Intelligence (SIGINT).

In brief, the campaign has taken significant gloss off Russia’s immense military prestige. It has exposed the limits of the country armed forces’ ability to engage in large-scale conventional warfare, which its predecessor (USSR) once dominated, against powerful adversaries. Friends and foes alike characterise the campaign performance as a disappointment and embarrassment for Moscow, especially given the epic WWII Victory of its mighty Red Army.

The conflict grinding on and taking a heavy toll on Russian troops amid increasingly capable and embolden Ukraine’s military are not the only major blow to Moscow. Reportedly, sweeping international sanctions have led to shortages of foreign-made components and bitten into some of its key weapon productions – materially crippling its supplies to the frontlines. As if that weren’t enough, Finland and Sweden unexpectedly dropped their decades of neutrality and applied for NATO membership.

This exacerbating situation begins to raise the temperature in Moscow, and seemingly the latter feels something has to be done. Whether out of frustration, desperation or both, Russian leaders publicly raise the stakes on the conflict by invoking the spine-chilling spectre of a nuclear confrontation.

In April, Russian foreign minister Sergei Lavrov warned the West of the elevated risks of nuclear conflict. At the same time, deputy chairman of Russia’s Security Council Dmitry Medvedev said his country’s nuclear doctrine does not require the enemy state to use such weapons first, Britain’s media outlet The Guardian reported. All the while, Russian state-owned TV station, Rossiya 1, aired a talk show where host and guest pundits dwelt on how many seconds it would take for Russian ballistic missiles to land in London, Paris and Berlin.

The West’s reaction to Moscow’s nuclear sabre-rattling has been until now a mixed bag. Some officials characteristically dismiss it as irresponsible or unwise – cautiously asserting that Russia is not the only camp holding stockpile of nuclear weapons. Others are more rattled and acknowledge that prolonged conflict in Ukraine will deplete Russia’s smart or precision-guided munitions while crippling international sanctions is already hampering its ability to replenish them.

The combined effect will likely wear out Moscow’s conventional strength to the extent that could potentially push it to rely on its nuclear arsenal, especially the tactical ones. On that point, CIA director Willam Burns is said to have warned in April that Putin’s desperation could result in the use of tactical nuclear weapons or low-yield nuclear weapons.

As a matter of fact, Putin already envisioned the possibility that Russia could one day resort to that option as he closely observed the Kosovo war in the late 1990’s when NATO conducted high-precision military strikes in Yugoslavia with great success. Back then, Moscow watched the campaign with deep concerns and felt that its own conventional capabilities were seriously lagging behind the US counterpart. To overcome that lagging, Putin, then-secretary of Russia’s Security Council, architected the principle of “escalate-to-de-escalate” which was adopted as his country’s new military doctrine in spring 2000. In essence, the new doctrine calls for the use of limited nuclear threats and strikes if Russia were to face large-scale conventional attacks that overwhelm its defence capacity. It is practically a defence strategy designed to deter the West from involving in conflicts in which Russia has a strategic interest or holds an important stake.

In military jargon, there are two types of nuclear weapons – strategic and tactical. The former can travel up to several thousand kilometres and carries high-yield warheads capable of wiping out an entire city and its multi million inhabitants. According to some estimates, Russia is believed to have over 6,000 warheads compared to 5,500 for the US.

On the other hand, tactical nuclear weapons travel a few hundred kilometres and carry low-yield warheads intended to mainly take out enemy’s large formations, forward bases, communication networks and logistics hubs in a battlefield. Russia is estimated to have about 2,000 tactical nukes with various delivery options by sea, air and land while the US’ stockpile is believed to be around 200, mostly are B61 thermonuclear gravity bombs designed to be dropped from warplanes.

The large disparity of tactical nuclear weapons in favour of Russia is not the only concern for the US military top brass. Some experts point out that unlike strategic nuclear weapons, there has never been a ratified international or bilateral treaty with regards to the development and deployment of tactical nuclear weapons anywhere.

For Russian leaders, the conditions for using limited nuclear strikes as established under their “escalate-to-de-escalate” doctrine increasingly solidify each day in the current conflict with Ukraine, which they now view and qualify as NATO’s proxy war. Barring the West scaling down its military involvement in the conflict, some experts fear that Moscow might opt to pre-emptively stage a tactical nuclear detonation over the sea or in the atmosphere to demonstrate how far it is willing to push back.

Should Russia choose that path, how the West would respond is anyone’s guess. For now, the more pressing question for NATO and its allies is how to appropriately punish what they call Putin’s Russia bad behaviour and deter it from subjugating other nations in the future without actually humiliating it.

Davan Long is a political analyst based abroad. The views expressed are solely his own