Except in today’s geopolitical climate, a Polish soldier on border guard duty next to Belarus or Kaliningrad really should be keeping his head on a swivel.
Putin’s “little green men” and weaponization of migrants (as well as “migrants” - i.e. not actually migrants, and possibly just people from prison told to “go here and make problems, and you get a pardon in Russia”) are well established and known tactics at this point.