Did Russia risk WWIII when they flew paratroopers into Belgrade at the end of the Kosovo war?
You mean after 1 day after Kosovo war ended? We are talking about '
escalate to de-escalate' a fresh war in Ukraine that may result in Nuclear WW3, not post-war peacekeeper squabbles.
5K troops would not be anywhere near enough to stop the Russians in a fight, but what happens if a unit of NATO troops just stood in the way of a major Russian advance and refused to move? Are the Russians going to open fire first on NATO troops flying NATO colours?
Russia may use tactical nuke against NATO troops, what will NATO do? Are the NATO forces going to retailate with nuclear strike against Russian troops? Where does this hypothetical end up? Nuclear WW3. There is no indication that NATO was willing to go nuclear WW3 over Ukraine.
Also, given the absolute chaos that is the Biden Presidency and the mess of conflicting interests that is NATO, could anyone guarantee there couldn’t have been a tail wagging the dog situation where an US underlying forced the issue by make a call out in the field or a rabidly anti-Russian power like Lithuania or Poland might have taken things into their own hands?
This is why Russian Intelligence Agencies exist, to gather options on a gradient scale of likelihood and present this to Putin. If Putin got fed info that NATO intervention was highly likely, then he should have issued nuclear threats to NATO leading up to the invasion, but he didn't, because it was not necessary.
Russia only mobilized nuclear armaments on high alert one week after the invasion, which suggest he didn't believe NATO intervention was likely leading up to the invasion.
Given the colossal costs and consequences, what degree of risk would you have been willing to bet that it won’t happen to take no precautions or safeguards?
The fact that Russia only put it's nuclear force on high alert one week after invasion (progress slow, NATO getting hardon with aid), suggest it did not view NATO intervention as a risk leading up to invasion, but viewed potential NATO involvement after the invasion. Russia would have put nuclear force on high alert if the risk of NATO intervention was high before the invasion, not send an overrushed, undermanned, and undersupplied force to surround Kiev to pre-empt a non-existent threat of NATO involvement.