he's stupid, thats why.
no matter how one looks at it, bijuus are better in a totsuka seal than in obitos hands.
even if akatsuki find out itachi did something to remove the bijuus from this physical world, they have no way to prove he did anything outside of beating him down and reading his mind.
As you already touched on, Itachi entered the Akatsuki to make sure they never threaten Konoha, but this also includes Konoha's "trick up their sleeve". As many if the Kages previously stated, the tailed beasts balanced power in the shinobi world. Killing and sealing Naruto would leave Konoha at a great disadvantage, something Itachi would want to avoid.
itachi wanted the entire world to be exterminated. he entered akatsuki to make sure they got their hands on the bijuus which theyd obviously use to start a world war and kill everyone. the tailed beasts are narutos equivalent of WMDs.
killing and sealing naruto saves the entire world from akatsuki having one more WMD in their possession. even if itachi spares naruto in part 1, which he didnt intend to do anyway, akatsuki will inevitably come back and still take naruto regardless.
the best course of action, if itachi is really an extremist who kills the few to save millions, is to kill naruto and seal him.
And another thing to add, Itachi is a pacifist at heart, sealing them away is against his nature.
itachi is a brutal evil mindrapist sociopath who exterminated his own family just because of a possibility that even mroe people will be hurt.
well not killing naruto results in an extreme probability of him being captured and used as a WMD on the world by a group of radical evil terrorist nutjobs.
menaing itachis a complete hypocrite for doing the extreme method one minute, and nothing at all the next minute.
He's not evil, that's why....
itachi is one of the most evil characters in the series. he tortured and killed innocent people, manipulated and lied to the world, and aided terrorists in obtaining WMD nukes, which ensures the beginning of the fourth shinobi world war.his whole motivation was supporting danzo and obeying his orders. he didnt give a shit about konoha. since danzo apparently "was" konoha.
Also, Itachi's personality is such that he doesn't cause conflict until he absolutely has to
itachis personality is that of a completely ruthless sociopath who tortured sasuke to insanity, and beat him into a coma just because he felt like causing sasuke as much pain as possible and turn him into his own personal puppet soldier
sealing them would blow his cover.
ITS ALREADY BLOWN. he basically already admitted to obito he isnt loyal to obito and wants to save konoha.
-He didn't know that Obito had spoken to Danzo and learned the truth. He also knew that Obito was the real mastermind. So the 1st point is entirely invalid.
he told obito he wants to protect konoha and sauske from him, giving away itachis whole motivations and allegiance. obi didnt need some elaborate story to figure out itachis not truly fully on his side.
itachi did think the whole time that obito= madara. so its obviously best for everyone he kill obito or do something to stop the bijuus being in his hands.
. itachi was loyal to the leaf, so was a spy in akatsuki,
itachi was loyal to himself so he helped akatsuki start a world war and did nothing at all to stop them wahtsoever.
-If he did that, they'd be sealed away forever. Seal away Naruto, and you cut down a significant source of Konoha's power. That would make no sense.
do nothing and akatsuki will still take kyuubi and use it to exterminate hundreds of millions of people.
do nothing and you waste a significant way of hindering the plans of a 100 year old madman.
that would make no sense...oh right. itachi doesnt make sense anyway so this is right in line with his bullshit.
. As for the other jins, Pain/Obito/other Akatsuki would not be pleased. All Akatsuki vs Itachi has an obvious outcome, with Itachi's death.
they have no way to know about any foul play and to find out if itachi really DID do something, they are going to have to use human path on him which kills itachi anyway. meaning if itachis innocent of sealing up the jins, they cut down a loyal soldier for nothing. akatsuki are many things, pragmatic is one of them.
To think of it...Obito knew Itachi's truth....So why didn't he told Pain that Itachi was a spy??
itachi wasnt doing enough damage to akatsuki to warrant any worrying. he is better off with a soldier in his ranks following orders, than a dead one. regardless of what little intel he leaked out. which couldnt have been much as itahci wasnt in the inner circle.
He was better off spying. Kishimoto stated, and in the anime as well that he just kept tabs on them.
he wasnt better off spying. keeping tabs on people who you know are gathering up WMDs obviously have plans to use said nukes and thus any measely intel you scrounge up isnt going ot be as helpful as ACTUALLY TRYING TO PREVENT ANY MORE NUKES GETTING INTO THEIR HANDS. you want something done, do it yourself. dont sit back and watch as akatsuki gets unstoppable power collected around them. its useless to spy on an apocalyptically evil madman. except to find out some sort of weakness to bring him down yourself. if itachi doesnt trust anyone to do this job but himself, then he should have spent all his time planning obitos death and a way to assasinate the other members.
like konan almost did.
self. Itachi didn't have anyone to report to at that point (since only Hiruzen/elders could know the truth), so he just made sure that the current members never hurt Konoha during his lifetime.
no he made sure that akatsuki became completely unstoppable by giving them NUKES
he tries to end it quickly and not cause physical injuries to his opponents, when he can.
itachi tried to sadistically torture kakashi for 3 days, then ordered his cold blooded murder for no reason. he also helped 6 jins be slowly tortured to death
Itachi randomly sealing jins would be entirely out of character and just bad writing tbh.
well if his "in character" is slaughtering his own family out of some murky sense of saving even more lives if he doesnt, then theres no reason why he wouldnt conclude that keeping bijuus out of madaras hands any way he can, is in the best interests of the world.
but itachi is a hypocrite who only "does whats necessary" when its safe for him to do so. for example, when his enemys sleeping and defenceless
, itachi's only interest was making sure sasuke ,naruto and the leaf ninja didnt get killed.
which they definitely will be when akatsuki launch their war and kill everyone.
itachis only interest seems to be making akatsuki unstoppable and handing over weapons of mass destruction to madara whom he knows to be evil and wanting world war.
that why he went to the leaf with kisame so he could negate the destruction and make sure nothing to serious happend while giving the operance that he wanted to take the kyuubi .
he went to the leaf to kill naruto and seal kyuubi.
if he had no intentions to do so, he wouldnt have separated jiraiya from naruto. only a fool or an evil person does that in that situation.
theres no way you can "negate the destruction" of killing off innocent people to get the nukes living inside them and then giving them to madara uchiha.
even obito didnt know he had access to them. which is why they make itachi invincible. the suprise factor of an attack with these wepons . litterally sealed the deal
itachi is faaar from invincible. and even if the weapons are, he isnt. how do you know obito didnt know about totsuka sword.
oro knew and was looking for it.
also if hes invincible then obito should be dead. which he wasnt.
simply cuz he knew itachi would solo him if he did.
why didnt itachi try to solo him ANYWAY?
Itachi wasn't trying to kill Kakashi or Sasuke with Tsukuyomi, if he wanted to he could have done so easily.
itachi wanted to murder kakashi which is why he told kisame to murder him.
also with that much mental abuse and damage, sasuke realistically would have died at his own hand eventually.
1. At the time Itachi told him to kill his friend, sasuke and naruto weren't friends with each other.
itachi still wanted an innocent person dead. he should have known anyway at the hotel and yet didnt retract his statements about killing your friends for power.
2. When Itachi used his genjutsu on Kakashi. Shortly after Kakashi said to himself "Why didn't he kill me, if he wanted to he could".
and seconds after that, itachi ordered kakashi to die at kisames hand.
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