“…there will be no peace in the tormented world, only a programmed and systematic series of wars and calamities—until the plotters have gained their objective: an exhausted world willing to submit to a planned Marxist economy and total and meek enslavement— in the name of peace.”

A remark to his private secretary, Lord Sandon, in May 1919. From Terence H. O'Brien, Milner, Viscount Milner of St James and Cape Town 1954-1925, 1979, Constable, p. 335.

1963, American University speech
Context: World peace, like community peace, does not require that each man love his neighbor — it requires only that they live together in mutual tolerance, submitting their disputes to a just and peaceful settlement. And history teaches us that enmities between nations, as between individuals, do not last forever. However fixed our likes and dislikes may seem, the tide of time and events will often bring surprising changes in the relations between nations and neighbors.

The Egyptians (1967), p. 241
General sources

Peace on Earth (1987), tr. Elinor Ford (1994) from Pokój na Ziemi, Ch. 2

Source: The Seth Material (1970), p. 274
Context: When every young man refuses to go to war, you will have peace. As long as you fight for gain and greed, there will be no peace. As long as one person commits acts of violence for the sake of peace, you will have war. Unfortunately it is difficult to imagine that all the young men in all of the countries will refuse to go to war at the same time. And so you must work out what violence has wrought. Within the next hundred years, that time may come. Remember, you do not defend any idea with violence. There is no man who hates but that hatred is reflected outward and made physical. And there is no man who loves but that love is reflected outward and made physical.

This attributed to Sun Tzu and his book The Art of War. Actually James Clavell’s foreword in The Art of War http://www.scribd.com/doc/42222505/The-Art-Of-War states http://www.collegetermpapers.com/TermPapers/History_Other/Sun_Tzu_vs_The_Wisdom_of_the_Desert.shtml, “’the true object of war is peace.’” Therefore the quote is stated by James Clavell, but the true origin of Clavell's quotation is unclear. Nonetheless the essence of the quote, that a long war exhausts a state and therefore ultimately seeking peace is in the interest of the warring state, is true, as Sun Tzu in Chapter II Waging Wars says that "There is no instance of a country having benefited from prolonged warfare. It is only one who is thoroughly acquainted with the evils of war that can thoroughly understand the profitable way of carrying it on." This has been interpreted by Lionel Giles http://www.dutchjoens.info/SunTzu%20-%20Art%20of%20War.pdf as "Only one who knows the disastrous effects of a long war can realize the supreme importance of rapidity in bringing it to a close."
Dr. Hiroshi Hatanaka, President of Kobe College, Nishinomiya, Hyōgo, Japan is recorded as saying "the real objective of war is peace" in Pacific Stars and Stripes Ryukyu Edition, Tokyo, Japan (10 February 1949), Page 2, Column 2.
Misattributed

Address to the Senate (22 January 1917)
1910s
Context: The question upon which the whole future peace and policy of the world depends is this: Is the present war a struggle for a just and secure peace, or only for a new balance of power? If it be only a struggle for a new balance of power, who will guarantee, who can guarantee, the stable equilibrium of the new arrangement? Only a tranquil Europe can be a stable Europe. There must be, not a balance of power, but a community of power; not organized rivalries, but an organized common peace.

All the Trouble in the World (1994)