At 99, Henry Kissinger is a living demonstration that you’re never too old to learn new things — or to unlearn wrong old things. The former secretary of state has implicitly acknowledged that he dramatically misjudged Russia, its war against Ukraine, and the qualities of Ukraine’s leaders and population. After Vladimir Putin described the dissolution of the Soviet Union and its repressive empire as “the greatest geopolitical catastrophe of the century,” suggesting it should be reconstituted, Kissinger urged America to “show greater sensitivity to Russian complexities.” After Putin invaded Georgia, Kissinger stated that “isolating Russia is not a sustainable long-range...