1. Your bag is highly unlikely to have been stolen as it was placed on a carousel in a sterile area and somebody had to carry it through CBP. That is a huge risk for that somebody. Almost a certainty that some fool grabbed the wrong bag and will figure it out when they get to their destination.

2. This means that there ought to be a similar but unclaimed bag in the sterile area at IAD. While this should be self-evident to TK, I would nonetheless ask them to check for unclaimed bags off the flight and perhaps they can quickly identify the likely culprit and reach out to them.

Hopefully your bag or at least its location is known in less than a day. Annoying, but not all travelers are rocket scientists.

If indeed your bag has been stolen, you will have a fight on your hands with TK. They will assert that their duty is to deliver the bag to the carousel and yours to pick it up. If you can get them to cover, the Montreal Convention sets a maximum -- stress maximum -- of approx. $1,700.

You may also have various insurances which might provide coverage here.