US President does not have the right to unilaterally declassify materials classified by allies

1. The claim by Andrew Exum on on PBS NewsHour that the US president has right to declassify foreign classified information is wrong on the facts and on logic. Presidential right to declassify US materials is not at issue. But by what legal authority does president have right to declassify secret materials shared by allies? As for logic, if president impetuously releases allies' shared secrets then the flow of shared materials will decline. There is no carte blanche. No good purpose--especially in a widely watched public forum--is served by inventing prerogatives that the president does not, in fact, enjoy. Add to the factual/legal and logical demerits of Exum's claim the handicaps that DonaldTrump enjoys by virtue of his incompetence.
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