The encouraging news from these talks was that the Russian delegation didn’t walk out and there are no reports of fights in the conference room.

In fact, the talks went on longer than planned, setting back the rest of the day’s agenda. On a day when expectations were low, these were all good signs – nothing, it seems, went particularly wrong.

But did anything go particularly right? Certainly there were indications of a slight thaw in the deep-frozen relations between NATO and Russia, with proposals for more talks in the future and the spectre of reciprocal offices being reopened.

Diplomats from NATO countries have previously told me that they are open to negotiations in certain areas, notably arms reduction and greater transparency over military exercises. It seems as if the Russian delegation listened to that proposal without throwing their arms up in the air. This may not have been a warm dialogue, but at least it happened.

The flip side to all this is that resuscitating a long-term relationship was only part of this meeting. The heart of it was focused upon tensions in Ukraine and, on that front, progress was a lot less obvious.

Jens Stoltenberg, the secretary-general of NATO, repeated his assertion that there is a real prospect of armed conflict on European soil. His problem, of course, is that Ukraine is not a member of NATO, so doesn’t earn the rights of protection that are afforded to members.

Under NATO’s famous Article 5, an attack on one ally is considered tantamount to an attack on all of them. Such is the principle of collective defence, which means, in reality, that an attack on a NATO member would lead to a military response from all of them, including the United States.

Ukraine has borders with a series of NATO members, all of whom are fearful of a Russian attack on their neighbour. But exactly how NATO would respond remains unclear.

Here in Brussels, Mr Stoltenberg talked of “severe repercussions” in the case of an attack, but, once again, put the focus upon using sanctions, rather than soldiers, as a deterrent.

The gamble is that President Vladimir Putin is dependent on Russia’s economic strength to maintain the backing of the country’s oligarchs. Sanctions, and economic damage, would hurt him more than the prospect of bloody battles or cyber warfare.

But the truth is that, among diplomats I’ve spoken to, there is unease and uncertainty. Mr Putin is seen as wholly unpredictable.

The assumption is that he won’t invade, but the fear is that nor will he want to withdraw more than 100,000 troops without having given them something to do; some reason for being there.

So it’s very hard to guess what happens next. At the moment, the terrain on the border is muddy and treacherous, which would hinder any invasion. And war might not even look like battalions swarming over a border – if this conflict comes, expect it to start with cyber attacks that disable crucial infrastructure and campaigns of disinformation.

Mr Putin knows that the world is watching him, but he remains emboldened by the fact that, seven years after he invaded Crimea, his troops are still there. And, perhaps, by the knowledge that some European countries, including Germany, are rather reliant on Russian gas imports.

“Logically, this ends with the Russians backing down,” one European diplomat told me. “But that’s our logic. Putin’s logic will be different. That’s why we’re nervous.”