Possibly no one had more influence on American foreign policy in the late 20th century than Henry Kissinger, who died last month at age 100. In his long and active career, he advised presidents, carried out policies and initiatives and was a highly visible figure around the world.

While it’s early to pronounce judgment on his legacy, it’s clear that his impact is deeply mixed. His accomplishments were both positive and negative. He was respected and he was reviled.

Kissinger is the only person to have served as national security adviser and secretary of state at the same time, positions he held in the Nixon and Ford administrations. He was brilliant and secretive, and he wasn’t much focused on the human cost of his policies. He was interested in strategy, not values.

He showed little interest in democratic governance or transparency. A creature of the executive branch, he seemed to almost scorn the idea of three separate and coequal branches of government. You sometimes got the impression he had contempt for Congress.

I was not close to Kissinger, but our paths did cross on foreign policy matters. I served in Congress, and we approached policy from different perspectives. Coincidentally, we were both connected to the commission that investigated the 9/11 attacks. Kissinger was the original pick to chair the group, and former Sen. George Mitchell was to be vice chair. Both stepped down because of perceived conflicts of interest. Former New Jersey Gov. Tom Kean chaired the 9/11 Commission, and I was vice chair.

Rep. Lee H. Hamilton shaking hands with Secretary of State Henry Kissinger; Rep. William Broomfield in the background. Circa 1969, courtesy of the Wells Library Lee Hamilton Photo Collection.

Kissinger’s view of the world, which he characterized as sober realism, may have been influenced by his background as a Jew who spent his childhood in Nazi Germany, before his family fled and settled in New York. He was a very talented man and, wherever he went, in academic, policy circles and government, he rose to power very quickly. In the 1970s, Kissinger was widely praised for his diplomatic work. When he was named secretary of state in 1973, a Gallup Poll found him to be the most respected man in the world.

He engineered President Nixon’s historic visit to China in 1972, opening the door to improved U.S.-Chinese relations and ultimately reshaping the geopolitical map. He promoted détente with the Soviet Union, helping to reduce Cold War tensions. In the Middle East, his tireless shuttle diplomacy improved relations between Israel and its neighbors. These were real accomplishments.

Henry Kissinger left quite a stamp on American foreign policy. He was a master of developing strategy and exercising power. But American greatness isn’t just about using force and gaining advantage. It also relies on our faith in democratic governance and our belief in human rights and the dignity of all people.

Kissinger shared the 1973 Nobel Peace Prize for negotiating the agreement that ended the Vietnam War. His critics found that highly ironic. During the war, Kissinger orchestrated the U.S. bombing and invasion of Cambodia, which expanded the conflict and fueled a civil war that eventually brought the Khmer Rouge to power, resulting in up to 3 million deaths. The Cambodia disaster was Exhibit No. 1 for critics who accused Kissinger of war crimes, but he was also tied to a brutal military coup in Chile, Indonesia’s bloody invasion of East Timor, a violent civil war in East Pakistan and other foreign policy disasters.

Kissinger later had a lucrative career in consulting. He clearly enjoyed being a celebrity, rubbing elbows with rich and powerful people and being photographed with glamorous women. He became a great figure on the social circuit in Washington. Getting Kissinger to attend your dinner was a big achievement.

Henry Kissinger left quite a stamp on American foreign policy. He was a master of developing strategy and exercising power. But American greatness isn’t just about using force and gaining advantage. It also relies on our faith in democratic governance and our belief in human rights and the dignity of all people. There’s a place for sober realism, but American foreign policy should be grounded in our values.

— Lee Hamilton is a senior advisor for the Indiana University Center on Representative Government; a distinguished scholar at the IU Hamilton Lugar School of Global and International Studies and a professor of practice at the IU O’Neill School of Public and Environmental Affairs. He was a member of the U.S. House of Representatives for 34 years.