Biggest mistake in human history?Watch
Heck, you could even choose Decca records failing to sign the Beatles.
Anyways, your thoughts please.
Yes, it's the Athenian Expedition to Sicily during the Peloponnesian War.
It happened and we all let it happen.
While that's not to say that the Crusades and the Dark Ages wouldn't have happened if Western Christian-based religions didn't have an incredibly ego-based God, I doubt that even half as many people wouldn't have been burnt at the stake for not following Catholicism if a Pantheon was involved (Pantheons allow flexibility, a singular God denies that).
It has caused and is behind the reasoning for all sorts of problems for the last 2000 years.
I eventually managed to get back to the present where everything is now screwed up! Everything's changed: Jesus killed Judas, Hitler won WW2, WW3 has caused widespread radiation, oh and Amy Whinehouse is still alive dafak!?
Sorry guys, but it's really hard to hold in a sneeze!...
I think it's when we crossed the armistice line which provoked the First Cylon War. By breaching the terms of the armistice, humans gave Cylons a reason to start a war. And 40 years later, this led to the Second Cylon War which saw the annihilation and destruction of all of the Twelve Colonies.
In the original, the Cylon War started over humans going to the aid of some unspecified alien race being picked on by the Cylons. Humans and cylons fight for 1000 years, which ends with a peace treaty which is cover for the sneak attack on the 12 colonies.
In the 2003 series, the first Cylon War is triggered by rebellion on Caprica of the robot-cylons. The second Cylon War did feature a breach of the Armistice Line by Adama in a stealth fighter - but the Destruction of the 12 Colonies had been planned much earlier by Al off Quantum Leap.