“I greatly admire the skill and aplomb with which you conduct our foreign policy,” wrote Henry Kissinger in a 2012 letter to “the Honorable Hillary Rodham Clinton.” The compliment was included as a handwritten postscript added to the printed letter. The Feb. 7 letter, which was released in a batch of emails from former Secretary of State Hillary Clinton, is a request that she help declassify documents from Kissinger’s time as secretary of state, which he says constitute “a unique record of a critical period in American foreign policy.”