Whatever happened to the imminent outbreak of World War Three? Earlier this month, you may recall, warnings about a “huge” Russian war game were everywhere, sowing alarm across the Western world. This could, we were told repeatedly, be Russia’s biggest military exercise since the end of the Cold War. “Massive” and “vast” were other adjectives used.

Military and media reports built Zapad-2017 – Zapad meaning West in Russian – into an almost unprecedented threat, but two particular claims stood out. Russia’s insistence that around 12,000 troops would take part was dismissed as a subterfuge; in reality, there would be upwards of 100,000.

Then there was intent. Such a major exercise, it was argued, could provide cover for a Russian land grab in Ukraine or even the Baltic States. Its proximity, in time and geography, to the 1 September anniversary of the start of the Second World War – Germany’s assault on Polish troops at Westerplatte – only seemed to lend the warnings extra credibility. With East-West tensions running high, we were on standby for World War Three.

So what happened? Zapad-2017 concluded earlier this week, by which time it had seriously fizzled out, in Western media terms at least. All that made the news was footage of President Vladimir Putin observing the scene through binoculars, and a report that three people had been injured when a Russian helicopter accidentally fired on spectators. The numbers are put, even by Western analysts, at somewhere between 10,000 and 17,000 troops taking part. No one has been invaded.

Putin watches Russia's military might on display in war games

And the Russians are enjoying a rare last laugh. They point out, with some justification, that their numbers were accurate, there was no dissembling, international borders were respected. All the Russian troops introduced into neighbouring Belarus for the exercise are going home, too. After all the Western accusations that Russia has been waging an information war with the help of “fake news”, who is disseminating “fake news” now, they ask. Is this not further evidence that Western opinion formers are stuck in the rut of Cold War stereotypes? They have a point.

One theory doing the rounds is that, with Zapad-2017, Russia contrived to set a trap which Western analysts and media duly fell into. More likely, I think, is that Russia is simply enjoying the novelty of finding itself on the right side of any information war.

But that leaves the real question – for us – unanswered. How did it come about that the scale and intent of Russia’s Zapad-2017 – its latest in the four-yearly Zapad series of manoeuvres – was so unrealistically hyped in the West to the point of presaging a new world war?

Behind the scenes, accusations are flying, with “the media” – the “irresponsible” media – as usual, in the spotlight. There is an element of truth in that, but only an element. The media does not usually invent, completely invent, what it reports. Especially with military and defence matters, their information comes from somewhere; they may also be given a steer as to interpretation.

In this case, the media – or, more accurately, some headline writers – can be accused of missing some nuance in the information they were given. Russia “could” field as many as 100,000 troops, “could” use the exercise as cover to invade Ukraine, and so on, may slip over into “will”. Possibility becomes certainty. This may be done out of ignorance, for effect, or, in some cases, because it fits an existing political agenda.

But the media is not where the information – or rather, let’s use the old word, “disinformation” – about Russia’s Zapad-2017 originated. Even a cursory look back over advance media reports about these Russian war games shows that they relied on sometimes anonymous, but more often named, sources – sources moreover that could claim some expertise in the matter in hand.

One of these was none other than the Secretary General of Nato, Jens Stoltenberg, who warned that Russia “has used big military exercises as a disguise or a precursor for aggressive military actions against their neighbours”, citing Georgia in 2008 and Crimea in 2014.

Then there was the British Defence Secretary, Sir Michael Fallon, who said the exercise was “designed to provoke us” and appeared to accept the estimate of 100,000 troops.

Many of the reports also cited political or think tank sources in the Baltic States, Poland or Ukraine, where – for understandable reasons – a view of Russia as a past and potential aggressor prevails. That a particular view is understandable, however, does not make it correct, especially in new or different circumstances.

The same applies to precedent. UK officials defended what some – myself included – would regard as the scaremongering of the UK Defence Secretary and head of Nato, by saying that Russia had a record of understating the numbers involved in military exercises so as to exclude international observers, and it was not unreasonable to suspect them of doing the same again. Something similar applied to the use of manoeuvres as cover for aggression – even though the relationship between Russian exercises and its Georgia and Crimea interventions are at very least contestable.

Vigilance, they insisted, should be the watchword. But vigilance – and being prepared for any eventuality – is rather different, in my book at least, from hyping a supposed threat from a routine Russian military exercise in a way that simply was not warranted by the evidence and served a sharply anti-Russian Western agenda. This was happening, it is also worth noting, even as “non-aligned Sweden” (so described by Nato) was conducting a Nordic area exercise which involved many Nato members, and shortly after Nato itself had held exercises in the Black Sea and before that in and around the western borderlands of Ukraine. Who, it has to be asked here, is threatening whom?