I'm thinking it should be the other way around. Practically a lot of people at peace are allowing the soldiers to move through on their way to another area: If you were Germany you could peace Russia so he could get to France.
The stealth units should be the ones that are excluded from the deal. Or maybe there should be something implemented into the game where if you're at peace with somebody, they can see all the units that you have in their territory.
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"Bitches ain't shit, but hoes and tricks"
-Mahatma Gandhi