Kalki avatar would not be a harbinger of destruction but total peace world over. Mankind equated Kalki avatar with destruction as advent of an avatar is always preceded by a war of Mahabharata magnitude. This does not mean Kalki avatar would precipitate a war. The battle of Dharma (righteousness) is inevitable. When the society reaches a point of no return there is no other solution. It is only in such times advents a messiah, savior to put the society back on its pedestal.
Advent of Kalki avatar means precipitation of world war 3, a man-made catastrophic calamity, a full-scale nuclear war in which about 20% population of entire world would perish. So much destruction worldwide and people would blame Kalki avatar whereas it is only Kalki avatar that shall provide the soothing balm to ailing mankind in times of need.
In the aftermath of world war 3 with about 1200 million people dead world over, the site would be so ghastly that life itself would lose its meaning. All materialistic tendencies would vaporize overnight. People want something to assuage their hurt feelings and in such times God Almighty ordained an avatar to advent and give teachings of spirituality to entire mankind.
Kalki avatar mounted with jnana wisdom of Bhagavad Gita and Upanishads (independent spiritual treatises) shall make entire humanity realize their folly of pursuing material riches than path of spirituality which directly takes a human being towards God.
In present times if one can reach God, if one can realize God, if one can reach state of enlightenment it is only through teachings of Lord Krishna in Bhagavad Gita. One single scripture Bhagavad Gita suffices for entire humanity to reach state of enlightenment followed by moksha salvation. Yet, there were no takers.
The original text of Bhagavad Gita containing 700 shlokas verses in Sanskrit along with Hindi and English transliteration is available for mere $1 from Gita press, Gorakhpur, India. A highly subsidized publication yet mankind looked elsewhere in the glittering riches of material world. It is only in aftermath of world war 3 human beings would realize true potential of Bhagavad Gita.