Henry Kissinger was the wisest of American foreign policy leaders and the most oblivious, the most farsighted and the most myopic, the one with the greatest legacy — and the one we should most study to learn what not to do.

I knew Kissinger only slightly (he worked to charm journalists, just as he believed in engaging other adversaries) but see lessons both in his accomplishments and in his catastrophes.

Kissinger was intellectually brilliant and knew it. He had a capacity to see around corners, perceive possibilities for change and then work tirelessly to achieve them. His deep familiarity with history, particularly of Prince Metternich’s “concert of Europe” early in the 19th century, informed his success at balance-of-power strategies and is a pretty good example of why studying history isn’t just for nerds.

China early in the Nixon administration was isolated and chaotic, with Red Guards rampaging through the country. But Kissinger saw opportunity and nurtured it in ways that led to the unimaginable: a presidential visit and eventually normalization of relations and an explosion of trade. Russia felt sufficiently outmaneuvered that it then invited Nixon to Moscow and signed a landmark arms control agreement.

Likewise, Kissinger saw that the Yom Kippur War of 1973 created not just a military crisis but also a diplomatic opening, and he engaged in a furious shuttle diplomacy that eventually helped lay the groundwork for peace between Egypt and Israel that transformed the Middle East.

Yet for someone so savvy about diplomacy, he was blind to the force of nationalism, and many of his worst mistakes involved his dismissal of small countries as pawns to be sacrificed — along with the people in them.