Belarus does not want any part of this war, even though they participated in it originally via free passage for Russian troops. But they but may be willing to move troops about to and fro to appease Russians. (They suspect that they may be next on the bear's menu.)
A quick look at the border regions shows that there are very few options for Belarus if they want to enter Ukraine. Most of the border is in the Pripet marshes. A corridor to the west of the marshes is somewhat open and the area to the east of the Dnipro river around Chernigov is open. The Ukes have had over two years to build defenses. They need not be heavy fortifications in the west. For the marshes it suffices to have light forces that attrit, fall back a bit, attrit, fall back, and so on. Supply lines are easily disrupted in the swamps. In the west, I think that a similar strategy would work when combined with some fortifications. For the east the terrain is open and the Ukes might need some additional troops.
But given the size of the Belarussian army and its relative lack of combat experience, I don't see them wanting any part of such fighting.
Belarus is by no means a match for Ukrainian troops.
It is a small country with even smaller population and weak and unreliable military.
If there is any war, it would be a walkover.
I do not think Lukashenko us going to risk it. It would be rather quick end of him.
It is looking more like an harassment, to help their Russian overlords in their troubled situation.
Hope you’re right ...
Nobody is getting out of kursk area, that was a wild gamble that did not work. West needs to stop encouraging the death.
Belarus has integrated their militarry with Russia. The air defense systems are a joint integrated system. Belarus has Russian nuclear weapons which have limited Russian oversight for the purpose of giving Russia pausable deniability if their they are used by the proxy armed forces of Belarus against Ukraine or NATO. Belarus is the proxy country on NATOs border that serves the same purpose for Russia as Ukraine for the USA.
A Belarusian incursion into Ukraine ties NATOs hands, and the strengthening of the Belarusian border north of Kiev serves as a reminder to NATO that their incursion into Russia may have opened that same proxy army invasion into Ukraine. I imagine that Belarus could send 15-30,000k into Ukraine if Zelinski fires on them, and in that mix of troops there might be advisors from Allied countries.
Zelinsi has run his course of being a useful idiot and is now a belacous liability for Britian, US.