C17 is Military transport. Ruling out that it is NATO equipment being sent to USA, seeing as the flow of materiel is in the wrong direction, my bet is that the plane is transporting new recruit 'Ukrainians' who are to receive basic training.
this, on the basis that Ukraine needs 40 000 new recruits a month to keep up with the Russian recruitment-rate, and that any conglomeration of troops in the Ukraine gets spotted and bombed to smithereens, so new recruits must be transported and trained in the West.
C17 is Military transport. Ruling out that it is NATO equipment being sent to USA, seeing as the flow of materiel is in the wrong direction, my bet is that the plane is transporting new recruit 'Ukrainians' who are to receive basic training.