I can still hear the battlefields of eastern Ukraine. Just a mile or so from us, thousands of Russian troops were dug in; shells landed nearby. It was so cold my phone kept switching off. Seven years later, Ukraine is heading into another sub-zero winter. And the Russian troops have returned.

Moscow has now massed more than 90,000 troops on Ukraine’s eastern border. Washington is briefing that intelligence suggests an invasion. Moscow says this is ‘alarmist’ and — as usual — accuses Nato of inflaming things.

How did we get here? In truth the conflict never ended, it just froze. But it’s also true that the relationship between Kiev and Moscow has tanked this year. Ukraine’s President Volodymyr Zelenskyy is a former TV comedian from the Russian-speaking south east who grew up in the post-Soviet tumult of the 1990s — and it is this, alongside his experiences in the entertainment industry and in media — that shaped him. His approach to sensitive issues like the speaking of Ukrainian over Russian, and the battles over history and culture, was never ideological. He just wanted everyone to get on.

Zelensky campaigned for a mandate to conclude the conflict with Russia. His administration was quietly keen to strike a deal with Moscow. Its first year in office was spent negotiating behind the scenes with the Kremlin in the belief that a deal was there to be had.

But Zelensky learned what all Ukrainian Presidents learn: Vladimir Putin is not interested ending the conflict — at least not now. Zelensky began to speak out more forcefully against the Crimean invasion of 2014 and the build-up of Russian armed forces on the Ukrainian border. The Ukrainian President is now telling Russian speakers in the east of the country to return to the Motherland if that’s where they see their future. It’s something the Zelensky of 18 months ago would never have considered doing.

The Russian presence in eastern Ukraine serves to shape the atmosphere in the country — the pressure can be intensified and relaxed as the Kremlin sees fit. This newest build up, though, seems serious. It certainly includes more elite mechanised battalions than before. Fighting has escalated recently and reports of Ukrainian troops getting killed now come in almost daily. But recent deliveries of Turkish drones have enabled the Ukrainians to mount more effective counter attacks against Russian armour and artillery. Relations between Putin and Turkish President Recep Tayyip Erdogan are warm right now, but Ankara has consistently sided with Ukraine in the conflict. This, in turn, may have prompted more aggression from Russia.

Right now, the Russians sense opportunity and they are doing what they always do: probing for weaknesses — seeing what reaction they get. Would they invade? Well, Moscow has problems. It mismanaged Covid and it’s perennially low on cash. On the other hand, oil is back up to $80 a barrel, so the Kremlin has the resources it needs to cause trouble — and Putin has invaded before of course.

Russian aggression has affected Ukraine not just physically but psychologically. The loss of Crimea and the assault on eastern Ukraine humiliated the country, but it has also brought it together. The invasion created a sense of community far stronger than anything that had existed before. The Ukrainians have built a formidable war machine since 2014 and have proven not only their capacity to fight but their social cohesion. I can’t remember the last time I read a report of sabotage behind the Ukrainian border.

The Kremlin takes opportunities where it can, and it sees an American presidential administration that bungled Afghanistan and is obsessed with China; it’s also Europe’s main gas supplier and winter is coming. The Kremlin will be more than happy to move its forces west if the costs are manageable.

No one wants to see a Russian invasion of Ukraine but, at the same time, if Putin decided to throw half of his armed forces of into the fray it’s hard to see who would stop him. The West needs to act — and soon. If you want to hurt Moscow, hurt the finances of the few that matter: signal that there will financial consequences for the Kremlin elite should Russian troops cross the border once again. It’s easy to do — all their cash is in the West.

But amid all the uncertainty one thing is sure. If those Russian tanks start to move in, the Ukrainians will have to fight on their own. No one is coming to help them.<//>