The uchiha clan was terrorists.
so is danzo then. or at least a thug committing a warcrime
remember they could have awakened MS if they watched their dear ones die. and konoha would bear more hatred.
sasuke didnt get MS and he probably was the most innocent and confused of them all.
His method wasn't right, but he had no choice and time wasn't by his side. He prevented a war, but carried on the name of being called a traitor of his clan and being a double agent ensuring the Leaf village is safe.
and then he ensured that the leaf village got massacred by doing nothing to tell them anything about akatuski, and helped start a world war by aiding akatsuki in murdering jinchurikis.
he had plenty of choices and chose the second worst option.
and no he didnt prevent a war. he delayed it.
He did .. he saved a village from a unnecessary civil wa
he didnt. he saved nothing given they didnt need his help to beat uchihas.
he let konoha get massacred by pain by doing nothing to stop him.
he let orochimru destroy half of konoha by doing nothing to even slow him down.
Saved many lives from the hand of ET
no he didnt. he killed thousands of people by ending edo tensei and freeing madara from the only thing still binding him.
ending edo tensei defeated the entire alliance and caused the worst disaster in thousands of years.
and besides even if madara is taken out, itachi still saved no one because no one but the kages were still fighting. the whole rest of the alliance had already gone to back up naruto and bee.
Spied on Akatsuki for konoha.
no he didnt.
And top of that he willingly saved narutos life many times from the hands of akatsuki
he declared war on humanity and helped them murder narutos jinchuriki brethren. naruto will surely die at the hands of nagato without alot of luck and because itachi saw fit to tell them nothing about akatsuki or their abiltiies.
They were planning a coup d tet from the start. Itachi did the right thing by preventing a civil war, which, in the worst case scenario, would have lead to a Shinobi World War.
they were plannign a coup not a massacre. they were just as scared and manipulated as itachi was.
itachi did the worst thing possible by committing mass genocide and murdering hundreds of people which ensured that other nations will see konoha as an easy target and destroy them. losing their strongest clan overnight = world war. aiding akatsuki and murdering jins = definitely world war.
so clearly iachi didnt care abotu preventing world wars given he helped start the worst war in history.
Name me those one thousand choices you are talking about

.
i cant but in any decision, anything we do in life, theres thousands of roads we can go down and thousands of choices we could make.
i believe in the multiverse theory.
so in one universe, itachi left more uchihas alive than he ended up doing, and the same result was achieved.
to stop a military coup all you should really need to do is knock off the ringleaders.
And btw, the sand village joined Orochimaru in attacking Konoha, maybe u forgot bahahaha
that only confirms that the other nations do not need an excuse to attack konoha and were not going to do so just because its in a civil war.
. The only one other choice somebody tried to say was kill the leaders, which inevitably would start a civil war and nothing would've changed
wrong. how can you wage a civil war with half a clan, most of which are women and kids?
itachi kills half the clan = same result as killing everyone, only with less loss of life.
you skipped this part "starting a revolution and the next day having a civil war anyway, I dont think others would accept murderers of own villagers and hokage like Uchiha as their leaders. "
if they do not want war then they are going to have to accept revolutionaries as leaders. and the whole reason for genocide was to avoid war.
the reason they didnt know what kind of person danzo truly was is because itachi is selfish and corrupt.