Xanthippe: Well there was an awakening if you want to call it that about 500 BC when the writings of Greek philosophers such as Plato and also ConfucIus and the teachings of Bhudda reflect that people were discussing treating strangers well and being just in dealing with slaves and people from other nations. See the 'Golden Rule' and particularly notice how Confucius used it 500 years before Jesus.
Perhaps, such issues were being discussed, but no written record has survived to our day.
Why across the world people decided to suddenly start using ethics in dealing with their fellow man we don't know.
One probable explanation is that these ideas were spread across the Asian continent (even the Pre-Socratic Greek thinkers were located in Asia Minor) by the huge trading network that's generally know as the "Silk Road." For example, in Richard Folz's, "Religions of the Silk Road," he describes how many religions 'borrowed' ideas from other religions and that the very first great missionary campaign was initiated by Siddartha Gautama (better known as the Buddha Shakyamuni ), he organised his community of followers (the sangha) so that the laity provided financial support to the monastic class and tied the spread of his teachings to the trading network that was spreading over the Euro-Asian continent.
It seems contradictory, that this organisational system, based on the accumulation of wealth by the laity, was used to spread a religion that promoted self-denial (at least, to the point of choosing the middle way), but that it was so organised seems clear from this quotation from the Buddha's dialogues:
Whoso is virtuous and intelligent,
Shines like fire that blazes.
To him amassing wealth, like a roving bee
Its honey gathering,
Riches mount up as an ant-heap growing high.
When the good layman wealth has so amasssed
Able is he to benefit his clan.
In portions four let him divide that wealth.
So binds he to himself, life's friendly things.
One portion let him spend and taste the fruit.
His business to conduct let him take two.
And portion four let him reserve and hoard;
So there'll be wherewithal in times of need.
Dialogues of the Buddha. Trans: T.W. and C.A.F. Rhys-Davis, Oxford University Press
This amassed wealth eventually became the source of finance for the building of the numerous temples/monasteries that dot East and South East Asia.
But more importantly, because of the changes that Buddhism underwent as it moved through different cultures, it provides insight into what happened to Jewish thought as it came into contact with successive empires that dominated the Jews. Traces of Egyptian thought, Greek thought, Iranian thought, Assyrian thought etc, can all be found in Judaism and therefore in Christianity.
It is not, as the J.Ws claim, the one pure religion given by Yahweh.
PS: The greatest Chinese exponent of Universal love (as opposed to the more limited teachings on love with distinctions, by Kongzi, also known in the west as Confucius), was Mozi, who lived between 470 and 391 BCE. Mozi's views on 'love' are really quite modern, and clearly (if you study them) more advanced that then teachings of Jesus.