Under what circumstances can you stop and or attack an unmarked military convoy entering your country from a hostile nation? If we condemn Ukraine for this, we condemn any nation for attempting the same. That's not how the world works. you don't get to disguise your military trucks as RC, then blame Ukraine for being very skeptical of the reasons as to why a disguised military convoy suddenly wants to enter a rebel-held area.
You are assuming the wrong things. That the trucks are filled with military equipment & hostile actors, that there is no coordination with aid organizations or the Ukrainian government, that it is an act of war.
You are ignoring practical realities- that Ukrainian citizens
need aid, that there would be an enormous backlash for an indiscriminant, shoot-first-ask-later slaying of a humanitarian convoy, that Ukraine can
afford to be zealous with their violence.
Even if it is their right to gun them down, that right is expected to be used with
prudence. Not with cynical pre-emptive cruelty.
What are the best & worst case scenarios?
Assuming the convoy runs the border,
Say Ukraine bombs the shit out of the convoy.
They'll either A. Expose a russian war-crime invasion, the ends luckily justifying the means.
Or B. They'll slaughter an unarmed humanitarian convoy who trespassed in their territory. International condemnation, Russia gets a fire lit under their invasion engines.
Say they don't bomb the shit out of the convoy.
A. The rebels get resuplied, get enough steam to resist for many more months. Civilians get aid, Russia gets brownie points with civilians, Ukraine looks like a bitch, but Russia gets further international condemnation for continued violation of Ukraine's sovereignty & possibly called out for perfidious use of ICRC emblems.
B. Civilians get aid, Russia gets brownie points with civilians, Ukraine looks like a bitch, Russia gets condemnattion for continued violation of Ukraine's sovereignty.
Now which of those looks more appealing for Russia? Compare the results from A: War-crime resupplying convoy or B. Humanitarian aid.
Not only should Ukraine assume it's a humanitarian convoy
because it's not the cruel thing to do, it is also more prudent ccncerning both the possible consequences of their actions and the likeliest reality, (it really
is filled with aid).
Again, gunning down the first truck in an effort to block the convoy is the last-ditch-effort because even then the benefits barely outweigh the costs in the information/pr war.