It is a given that the Chinese invented the crossbow and gunpowder well before the time of Christ. It is also a given that they were a closed society until the early 1900's.
Until the Roman empire came along the Greeks had city states and everything else in Europe was unorganized . With the advent of the Roman empire societies began to form and Rome with its legions ran all of Europe. Not much changed for 1200 years everything was done the Roman way. Between 1200 AD and 1300 AD a new weapon began showing up in Europe. The crossbow came with trade and now the Knights and their Kings could not defend against it. For hundreds of years society was run by the ruling class held up by the power of the warrior Knights using their swords and longbows to enforce whatever laws the King wanted. Now any peasant could learn to shoot a crossbow in a few days and the Knights armour could be penetrated making Knights and their amour obsolete. This had a profound effect and began changing Europe's society. Within a few hundred years gun powder was introduced along with the canon. This made castles obsolete as a secure place to defend ones kingdom. The time of the Knight was over and society was again affected by war and trade.
Except for small regional wars all was quiet until world war 1 broke out in 1914. This energized the industrial revolution and The United States of America brought its might to bear against the Axis powers. After World War One the United States tried to return to its pre-war neutral stance. When World War two came along in 1940 The United States started producing war material and that sparked more research and development which pushed society forward again.
America got involved in two more wars in the 1950's an 1960's and this was the time that the computer was invented.since that application warfare trade and history have skyrocketed to unimaginable heights and taken turns that no one could have foreseen.