Now here's a head-scratcher...
Just back from Toronto. Flew in to ORD on UA. Toronto, like most major Canadian airports, offers "preclearance" on flights to the US (which most of you know). For all intents and purposes, once you clear Immigration and Customs, you're back in the US. But the security screening is clearly Canadian. Now they do a decent enough job, but they aren't nearly as strict as TSA. No shoe carnival, no cranked up WTMDs (I forgot to remove a belt that always alarms in the US, and didn't in Toronto). Laptops out, but go right ahead and place your coat on top of your laptop. I suppose the thinking is that all the Immigration and Customs rigamarole will tend to scare off the bad guys, but if you get through that, you're free to roam your destination airport and grab a plane anywhere.
Which again leads me back to my usual complaint: consistent inconsistency. In another post in this thread, TSAMGR made the usual point that inconsistency is designed into the process to keep the bad guys off balance. I'm thinking he said that tongue in cheek because, as we have documented here in numerous posts, the same airports do things the same way every time. They are clearly inconsistent with other airports, but never inconsistent from trip to trip through that airport.
And it seems to me that if we're going to have "preclearance" in other countries, then their screening has to be to the same basic level as TSA in the US. Consistent inconsistency is what I call a security breach waiting to happen.