WARNING: The following contains spoilers for Boruto: Naruto Next Generations Episode 176, "Blockade the A-Un Gate," now streaming on Crunchyroll.
Naruto always wanted to fix the sins of Konoha's past. He desired a more open-minded society; a village that wasn't just friends with other regions but also one that healed its own civil war with the Uchihas. It's why he was hellbent on redeeming Sasuke and saving the entire shinobi world from the likes of the Akatsuki and Kaguya. Now that he's leading Konoha as Hokage and trying to effect tangible change to ensure diplomacy and relations are kept in order, the latest episode of Boruto deals his vision a huge blow. Naruto's greatest fear comes to life -- a traitor exists in his midst.
When Naruto's council meets to discuss the recent fight against Deepa, Victor, the God Tree clone and the invisible Kara network, they're at a loss how to handle the situation. The terrorist cell is quite adept at keeping secrets, but upon further dissection of intel from Konohamaru and Sai, it's revealed Victor and co. knew about Momoshiki. This was the alien, another Ōtsutsuki clan-member first seen in Boruto: Naruto the Movie, who tried to kill Naruto and Sasuke, but the shocking thing is this battle against him and Kinshiki was kept secret.
These files weren't supposed to leave the village yet Kara got ahold of the info, leaving Naruto and Shikamaru cynical as it means they've got a spy at home. Shikamaru's eager to lock the village down by shutting the main gate, reiterating that since Naruto's alliance, Konoha has opened its doors to everyone: from friends to strangers to refugees. Naruto has always wanted cultural exchange, freedom of movement and so forth, but his advisor now thinks this has bitten them in the backside.
The council, which includes former Hokages Kakashi and Tsunade, leave it up to Naruto but he's torn as he knows there's danger in letting Konoha remain open. Ninjas could infiltrate, especially Kara's agents, yet he can't bring himself to justify the decision as it's not what predecessors such as Hashirama or his dad, Minato, would want. Admittedly, there are merits to this as desperate times call for desperate measures, and Shikamaru just wants to control the situation and properly investigate to find the culprit.
Ultimately, Naruto opts against it after conferring with Kakashi and remembering the past when he sees Boruto, Sarada and the other kids being hopeful and happy. He doesn't want to return to old, fearful ways. The shinobi world feared Konoha, especially as past warriors and leaders such as Madara and Tobirama were cold and aggressive in terms of inviting people in, which created many enemies. Numerous wars were fought and it led to the Akatsuki forming, so Naruto thinks it'd be a regressive step if he starts treating people like outsiders again.
His council trusts him, but there's a catch -- they know they need to improve their chakra sensory barrier. This is to ensure locals move freely in and out, while strangers are flagged and interrogated. We saw this in the manga when Koji Kashin and Delta had to slip in on behalf of Delta, so now we know what it's tied to as Naruto hopes to determine who betrayed them.
