Iran invades Afghanistan

Sort of. It's the kind of thing that goes on all the time on our own border, apparently, but Afghan troops shot it out with Iranian "security forces" (revolutionary guard? counterdrug patrol?) who strayed 100 yards over the border into Afghanistan. One Afghan and one Iranian were killed.

It's possible the Iranians got lost or were in hot pursuit of some drug traffickers. It's also possible they were up to no good.