How far away are we from the first Russia-Nato clash?

If this war in Ukraine continues for months, if not years, there will be a moment when Russia and Nato clash. It is inevitable unless both sides, by which I mean Russia and the alliance, deliberately ignore what each are doing for the sake of avoiding the third world war. This is what is going on at the moment. Vladimir Putin knows, because it's all being done overtly, that the US and the rest of Nato are supplying a fantastic amount of weapons to the Ukrainians. Nato has totally given up all that early caution about what weapons they supply to Ukraine. Now the full gamut of weapons are being considered or are already in the pipeline, including MiG-29 fighter aircraft, T-72 tanks, armoured personnel carriers, Mi-17 helicopters, S-300 air defence missiles and howitzers. It's a staggering list. And so many thousands of portable Stinger anti-aircraft missile launchers have been supplied by the US that the production line can't cope with demand. Putin watches all this stuff arriving and so far has done nothing about it. It is extraordinary and bizarre. Russia has satellites keeping an eye on everything, so Putin must have a pretty good idea by now the routes taken by all the arms convoys. When is he going to authorise a bombing raid to take out the convoys? There are two reasons why he has not yet done so. First, if he sends ground-attack aircraft to do the bombing, the chances are they will be shot down. The convoys are being masterminded by US European Command and they must have seriously effective protective measures in place to defend them from attack. The second reason is that Putin has to be worried about the frightening escalation that would erupt if he bombed or tried to bomb the convoys BEFORE they reached the Ukrainian border. That would lead to instant retaliation by Nato. So, as a result, the convoys continue to pour into Ukraine without any meaningful attempt to disrupt them and, for the moment, Putin has not declared that the convoys are an act of war. The reality is that the Nato arms supplies have moved from defensive weapons to outright offensive systems. It's a Nato war by another name. I fear Putin will not put up with it for much longer.