The fact that transit visas are something you need to apply for, pay fees, and risk being refused (and that going into a permanent record) makes no sense for me.
For the same reason, on return, I couldn't bring back any Japanese booze from the airport. I had to go through a second liquids and customs check at YVR.
So if you are coming off/going to a US flight from an international one you have to go out and back in. There is a US <-> International security gate but it's not normally staffed
And screw ups happen - I lost a Lufthansa bottle of champagne they gave me on board for screwing up my seat. At a change in Frankfurt the we had to be bussed from the plane to the terminal - the bus dropped us outside security and I lost the sealed Lufthansa labeled champagne to the security desk.