Cope tires on Su-34 to protect against hollow charges and kinetic energy penetrators. Together with the metal airframe, it acts like NERA to protect the precious tarmac.
The sole tire around the wingtip jammingpod is like a cherry on a pie.
Probably because rubber, which is often used in radar absorbent coatings or RAM, interferes with radar. In this case, might be SAR or ISAR being used by satellites. The resulting satellite image either doesn't look like a plane or it would vaguely look like a plane in fragments.
I doubt it's used to protect against charges.