Love Jihad began the day the first Muslim conqueror entered Hindustan. Why? For example, Babar might have been accompanied by his begums. But what about all his subordinates and soldiers? At the end of a battle, were women waiting to fall in love with all his subordinate and soldiers? The women were either forcibly taken into the harem or purchased or otherwise induced. In case of nikkah the women had to be converted. This was the beginning of love jihad. In other words every Muslim or Momin is carrying in his vein some kafir blood.
There is a key difference between a Hindu girl marrying a Christian boy and marrying a Muslim young man. In the first case, the marriage would be monogamous. If he is a Catholic, the marriage is a sacrament and not a contract and therefore no divorce is possible. Whereas the Muslim young man can divorce his wife at the drop of a hat. As well as, he is free to marry several women. This would explain that there is no public protest when a Hindu girl marries either a Christian or a Jew or a Parsi. This is what the defenders or decriers of love jihad must realize.
Jihad or Holy War is enjoined by the Quran and Hadith upon every Muslim to fight for his religion. In the case of love the factor of jihad comes in because the man not only wins a woman for Islam but also all the children that she begets. Prophet Muhammad had exhorted his followers to make their marriages prolific so that sooner or later there would be more Muslims in the world than any other people.