Didn't stop WOC 2007 being awarded to Ukraine?
Come to WA for underwater orienteering!
Or MTBO to Israel with "you will be safe as the range of bombs is 5km from the event site."
While I was making it in a slightly flippant way, there's a serious point in that a fairly significant number of countries where orienteering isn't currently practised are sufficiently politically unstable that their forests are places where rebels might hang out, which means they're probably not particularly safe places to be, and the military probably wouldn't appreciate your being there anyway. (There are also the places which are peaceful now but still riddled with landmines from the last war, which is why, I presume, Bosnia-Hercegovina is the one country of the former Yugoslavia which isn't in the IOF).
I've heard a few good stories from Northern Ireland orienteering in the 1980s about how they would occasionally encounter IRA training activities - it seemed that they operated on a 'We'll ignore you if you ignore us" basis.
My favourite is the obligatory information on all orienteering events in the Ural mountains: "There is no danger of radiation in this area."