This war - with plenty of crimes to the people of Ukraine, where most of our common conventions have been trespassed, wartime treaties ignored, and more worrying, when being called upon them Russia has resorted to its usual propaganda and obliviousness when referring to its “special operation”.
Context for this initiative
It’s understandable NATO members and other governments didn’t want to intervene (because of the consequences of such intervention) on the first phase of the war and abide by the playbook of what succeeded in the past with the Afghanistan war; supplying locals with weaponry so they could defend themselves and their country.
Since that became a successful strategy (obv. depends on who looks at it and with which lenses…) that’s what the west has used. It also has used many sanctions against Russian individuals and banks, cut out investment, freeze assets, etc. All in all powerful moves, yet we (and pretty much most of the world) still depends on Russian oil and gas. Also, all countries economies have been linked together in a global scenario so it’s not too clear how this will help if Russia defaults on its loans. This seems very calculated financially but surprises might still happen.
We can call the first phase of the war phase 1, but we are no longer in phase 1. The Russian state has threatened (indirectly) many countries (including the UK), showing off their “military power” through the showcasing of some of their new “toys”.
After ignoring treaties (and threatening other countries too!) we can move to a phase 2 scenario, where escalation with other countries is possible. However, we are already far passed phase 2 and went on to phase 3 or 4 depending on how you look at it.
Since Russia is losing big time based on its original plan - it has treated to use nuclear weaponry, and chemical and biological agents. And worse, this will be used against civilians without blinking - just look at what they have done in the last few days with personnel landmines…
All the above is prohibited in a global scenario with the very real possibility to things getting out of hand.
So we are, all, together playing in this theater, moved to an alert state and rapid-reaction mode. But, there is not much we can do once one of these is deployed. Our best bet is to end up the war quickly. And for that, like for many other things highlighted here, I have ideas.
What we can do
Something governments could do without entering in direct confrontation but is not happening is to give its soldiers paid leave to do what they want - they can go sit on their sofa or they can go fight in Ukraine. Both scenarios are possible, but one is more likely than the other. If even that would be an issue we could do the same with a “temporary leave” and pay their salaries from taxpayers money (maybe 1% allocation) or with donations.
That can’t be understood as direct confrontation from NATO members but will certainly make a difference in the warzone in Ukraine.
The benefits of the above are clear, more soldiers, better equipped and trained (especially around the weapons these countries are sending).
There is more stuff we could do, indeed. We could lease military equipment, not all and not many, but with the proposal above, we have trained personnel who know how to use these machines effectively deployed in the right location without compromising national security of any NATO members.
 The whole military exhibit Russian is doing, similar to the one in North Korea and even China, has an eerie resemblance to the USSR demonstrations - but we should remember all in the world got to their knees by a single country during WWII. There are many reasons for it, but what’s scary is if just a few errors didn’t occur that country would have won square. The USSR was no rival and the Russia of today would be even less so. The USSR invested big amounts of money in research and invention - today’s Russia does not - which for the purpose of ending this war is good.
 This is based on what national military have as of now. There are ways these could not just avoid but render useless some of these in a battlefield - but none of what I’m talking of is available to these military bodies.