Whether history teaches us to be optimistic or pessimistic is
only a matter of when and where you choose to look.
There have been wars at least as long as there has been civilization - which of
course continues to today.
Empires have risen, Persian, Chinese, Mongolian, Ottoman, Aztec, Inca, British,
USSR.
Some lasted for centuries, some covered the majority of the world (that the
culture knew of).
Every one of them fell, for one reason or another, eventually.
That could give hope that the US, which is extending influence both culturally,
politically, and militarily throughout the world, will inevitably follow - but
its seems obvious that it will be replaced by another - no matter the ideals in
begins in, it will inevitably grow corrupt. They all do.
In the 3rd century BC the Egyptian library/museum at Alexandria
contained the collected knowledge of the Egyptian and Greek civilizations, the
largest in the world. While the circumstances of its destruction are debated,
it was apparently due to some combination of war and religious fundamentalism.
The civilizations of the Mediterranean created, among other things, plumbing,
calculus, and democracy (but only for white male property owners) - and at the
hight of the Roman Empire, a popular spectator sport involved watching humans
fight to the death, and eventually flooding the coliseum to create mock sea
battles - but with real weapons - for the entertainment of government and the
wealthy.
In the Dark Ages, as Rome fell,
much of the infrastructure was allowed to fall to ruins, and everything from
libraries to aqueducts was lost - along with the education and intellectual
development that had accompanied it, and much already acquired knowledge and
technology was lost.
Then came about the forced conversion of people in Europe,
Asia, and Africa to Christianity
and Islam, as well as wars between the two (the Crusades) - ultimately
spreading throughout the world, and, of-course, lasting to the present.
Europe's renaissance consisted largely of no more than
the re-discovery of things which had been previously known, but lost.
For every Ghandi there has been a Hitler and a Mussolini. For every Roosevelt
and Carter we've had a Regan, A Bush, and a Bush Jr. Lenin's "people's
revolution" turned quickly into Stalin's purges.
Che failed to start a revolution, and after all of Chavez's work, today
immigrants still work in pesticide laden fields for far less than minimum wage
while middle class Americans with far more comfortable lives advocate
criminalizing them for it.
For all the noise the anti-war movement made, American troops pulled out
because the North Vietnamese won.
In fact, the non-violent success Ghandi seemingly had happened to be at a time
when the British Empire was already in decline with Canada, New Zealand,
Australia, South Africa, Egypt, and Iraq becoming officially fully independent
in (or around) 1931, and their military over extended worldwide - a guerrilla
war with Ireland, the aftermath of WWII, and calls (and actions) for
independence throughout the British Empire in Asia, Africa, and the Americas.
For 40 years India
had sought independence, but it was not until these - often violent - worldwide
events came along that it was finally granted.
Then, almost immediately, (as British representatives had predicted) the
country split, and the potentially violent stand-off between newly formed Pakistan
and India (both
of which have nukes) has lasted to this day. So much for non-violence.