A few weeks from now on February 24, the Ukrainian leader will mark a full year as a wartime president.

A year since his famous rejection of a US offer of safe passage out as Russian tanks rolled across the border and intelligence suggested Zelensky would be targeted by Vladimir Putin's hitmen prepositioned in Kyiv.

"The fight is here. I need ammunition, not a ride," a defiant Zelensky was reported by AP to have respectfully told the Americans according to a diplomat with direct knowledge of the exchange.

How admirable and prescient, that response.

There can be no doubting Zelensky's success. We had been told by defence experts that this asymmetric war would be short as Russia's twin advantages in fire-power and numerical troop strength overwhelmed the western-adjacent but non-NATO-aligned Ukraine.

Since then, Putin's criminal bloodlust has been met by a Ukrainian population driven by something missing from the Russian grunts compelled to fight, the do-or-die defence of the Ukrainian homeland.

This national resolve has held up, indeed hardened, as Russian missiles slammed into residential apartment blocks and struck the ramparts of the Zaporizhzhia Nuclear Power Station in south- eastern Ukraine, the largest nuclear power plant in Europe.

Russian forces captured the facility with reckless disregard for the consequences in March and remain in control of it, with Ukrainian employees and some international technical experts still in situ.

However the greater plant has sustained shelling throughout the conflict, raising serious fears of a radiation release, or even a meltdown if cooling equipment is compromised.

Reuters reported on Friday that the situation is deteriorating due to maintenance difficulties and "psychological" strains on the captive Ukrainian workforce.

"It is getting worse not only because of the mental state of the remaining Ukrainian specialists but also due to the condition of the equipment," Energy Minister German Galushchenko told Ukrainian television.

Meanwhile, it has been reported also that some Russian government buildings in Moscow are being fitted with anti-missile air-defence systems, suggesting that Putin and his lackey generals are contemplating the possibility of defeat and even of the conflict extending into Russia as western-backed Ukraine gains the upper hand.

Former Russian president and now deputy chair of the security council of Russia, Dmitry Medvedev has thrown subtlety aside, warning that if Russia were to lose a conventional war, then an obvious outcome would be a nuclear strike.

This unthinkable possibility is of course, now having to be thought about. It comes with the simple reality that direct conflict with a nuclear power carries the risk of the ultimate retaliation if defeat appears imminent.

Should we be surprised?

After all, why do great powers maintain these colossal destructive powers if not to use them as last resort? And in an oppressive state such as Putin's Russia, a threat to the country and a threat to the regime are apt to be seen as the same thing.

For the West, it is of a piece with the persistent imponderable running underneath this entire conflict, which is how do you win a war, that you are not actually fighting yourself?

Everybody wants Kyiv to prevail but no third country has its boots on the ground fearing this would amount to declaring war on Russia. Nuclear-armed Russia.

For its part, Moscow has increasingly seen this as fine distinction anyway, especially as advanced artillery and missile defence systems from Europe, Britain and America alter the balance. Its view is that if the West is arming Ukraine and shifting Kyiv's capabilities from being merely defensive to potentially offensive with the capacity to reach targets deep inside Russia, including the capital, then it is tantamount to involvement anyway.

As the war enters its second deadly year, there are now fears it is heading towards some kind of stalemate, where huge loss of life and untold hardship continues, but the prospects of clear victory for either side recedes.

Few can imagine a Russian retreat back behind its own borders, but neither does it seem likely that Zelensky's Ukraine will cede territory to the Russian aggressor.

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While Putin's aggression united the West, Europe still has its hawks and doves. A meeting of defence ministers in last two days in Ramstein Germany, failed to resolve an impasse in which former Eastern bloc countries such as Poland and Estonia want to donate German Leopard II tanks to Kyiv but are so far barred by Berlin as the source country. Germany's nervousness reflects longstanding hypersensitivity to Putin's eggshell ego, even after Berlin abandoned its post-WWII pacifism at the start of the war.

Estonia has reportedly committed more than 1 per cent of its GDP to the Ukraine defence cause. Sweden has just agreed to provide 50 of its CV90 infantry fighting vehicles and its Archer mobile howitzers.

Australia's most recent contribution is a 70-strong contingent of troops to train Zelensky's reservists (in Britain) and enable Ukraine to "stay in the fight", as Defence Minister Richard Marles put it.

As the bleak northern winter releases its icy grip, the West needs to form a real-world understanding of what "staying in the fight" actually means - not least for the thousands of civilians likely to die for principles that may be undeliverable and for which we are not prepared to directly fight for ourselves.