“Military men are the scourges of the world.”

La guerre! C’est une chose trop grave pour la confier à des militaires.
Variant translation: War is too important a matter to be left to the military.
As quoted in Soixante Anneés d'Histoire Française (1932) by Georges Suarez
War is too serious a matter to leave to soldiers.
As quoted in Clemenceau and the Third Republic (1946) by John Hampden Jackson, p. 228; this has also become commonly paraphrased as: War is too important to be left to the generals.
Post-Prime Ministerial

Source: As We Go Marching (1944), p. 104

Kissinger has denied saying it.
The only evidence that Kissinger ever said this was a claim in the book, The Final Days, by Bob Woodward and Carl Bernstein, in chapter 14 (p.194 in the 1995 paperback edition). Woodward & Bernstein claimed that one of Kissinger's political foes, Alexander Haig, had told someone unnamed, that he (Haig) had heard Kissinger say it. That's triple hearsay, made even weaker by the fact that one of the parties is anonymous. Kissinger has denied ever saying it, and it was never substantiated by Haig, nor by anyone of known identity who claimed to have heard it. As Kirkus Reviews noted about the whole book, "none of it is substantiated in any assessable way."
In fact, the quote is not even very plausible, on its face. Kissinger served with distinction in the U.S. Army during WWII, and was awarded the Bronze Star. He has always been very respectful of other servicemen and their sacrifices. For him to have said such a thing would have been wildly out of character. In fact, the awkward phrasing doesn't even sound like Kissinger, whose English prose is consistently measured and careful, despite his heavy accent, even when he speaks extemporaneously.
Misattributed

Source: {DCJ 16, July 2018}

Choruses from The Rock (1934)

Interview to CNN, January 7, 2020 https://www.youtube.com/watch?v=PyH6QmFmeZE
Interview to CNN

2016, Remarks to the People of Cuba (March 2016)

“Liar, liar, abaya on fire,” http://www.wnd.com/news/article.asp?ARTICLE_ID=27264 WorldNetDaily.com, April 17, 2002.
2000s

Dedication
The 25-Year War: America's Military Role in Vietnam (1984)