There was only one Henry Kissinger

An important part of Realism is being willing to turn a blind eye to human rights violations in the interests of furthering great power relations. This meant that Kissinger supported the 1973 overthrow of the Allende government in Chile and giving Indonesia the go-ahead in its 1975 invasion of East Timor.

Finally, Kissinger was also a realist about his own personal advancement. In 1968 he stopped advising Republican president hopeful Nelson Rockefeller (Rockefeller family money had helped finance his academic endeavors for over a decade) and jumped ship for another hopeful: Richard Nixon.

Once out of office Kissinger became very wealthy vis Kissinger Associates privately advising people, governments and corporations he had encountered in his US government roles. After the 2001 "9/11" terrorist attacks he was invited by President Bush to chair a commission of enquiry. He had to resign because he would not disclose the list of clients advised by Kissinger Associates (which may have included Arab governments). He made a lot of money out of his friendship with the Chinese government.

In short, Kissinger was a major figure in both the study and practice of International Relations. His adherence to Realism enabled him to be seen both as a person who worked to improve US relations with traditional enemies and yet also a person who sacrificed others to achieve those ends.

Owing to the fear that Kissinger would be sought as a war criminal, the US government refused to join the International Criminal Court – national political interests and prestige were derailed to protect one individual. Now that he has gone, this would be a good time for the US to join its allies (such as Australia and the UK) as a party to the ICC.