Having covered American diplomacy for a decade now, I’ve received many “diplomatic” answers to my questions — but none more so than “Yes, but not really.” I was reminded of it by the recently negotiated Open Skies aviation agreement between the United States and Japan.

The idea of the Open Skies accords, which Washington has with more than 90 countries, was to liberalize air travel between the signatories, allowing flights from any city in the first country to any city in the second without the previously imposed government restrictions. However, the deal reached with Japan in December has one glaring exception…