Cluster Munitions for Ukraine

(CNN) What are the cluster munitions the US is expected to supply Ukraine and why are they so controversial? Quoting,
The United States is expected to announce a new military aid package for Ukraine on Friday that will include cluster munitions for the first time, defense officials have told CNN.
In January, in Tanks for Ukraine, NFG? I wrote,
The Marines have turned in their tanks, mandated by their new littoral mission. A general principle can be distilled: Stealth multiplies lethality. Is it impossible to employ armored spearheads in Ukraine? If the abysmal performance of the Russian army continues, it is conceivable, though such assumption receives warning from von Clausewitz. Paraphrasing, the  enemy does not do what you want him to do; he does what he wants to do, which could be competence with the 9M133 KornetCluster munitions would be far more useful to Ukraine.
With little change, the argument of Tanks for Ukraine, NFG? , which is based on the characteristics of the modern ATGM, can be extended to tank vulnerability to air power when air superiority is lacking. It does not extend to artillery,  or cluster munitions delivered by artillery, which has greater possibilities of dispersal and camouflage.
Cluster munitions will be an effective force multiplier for Ukraine.