Be careful!
A former PM of Norway has supposedly been detained for an hour because he travelled to Iran in 2014.
On a diplomatic passport.
http://wjla.com/news/local/former-norwegian-prime-minister-held-for-questioning-at-dulles-airportMy experience with customs agents around the world makes this story very plausible.
Canada isn't bad, American customs are on the stupid side, Vietnamese/Laotian/Thai/Cambodian/ try to be unpleasant but you can tell it's not in them, Hong Kong are efficient and full of common sense, Greeks like their submachine guns but intimidate no one, the Dutch/Swiss/Germans/French are reasonable, efficient-ish.