If Russia disconnects from the internet, won't there be two separate network of the same blockchain?

I've recently came across this BBC article saying Russia is going to be using their own network.

Hypothetically speaking, if they do get that and still run bitcoin (or any other cryptos) nodes on their own, wouldn't they just keep adding completely different blocks to the rest of the network in the world and not have any interaction with each other?

What would happen if the two networks join when they reconnect back to the internet again? Would they just reset all of their account deposit and revert back to where they were before? Or if their hash rate is higher than 51%, would the rest of the world be affected by this?

I'm curious and somewhat concerned. Any ideas?

You can get bonuses upto $100 FREE BONUS when you:
💰 Install these recommended apps:
💲 SocialGood - 100% Crypto Back on Everyday Shopping
💲 xPortal - The DeFi For The Next Billion
💲 CryptoTab Browser - Lightweight, fast, and ready to mine!
💰 Register on these recommended exchanges:
🟡 Binance🟡 Bitfinex🟡 Bitmart🟡 Bittrex🟡 Bitget
🟡 CoinEx🟡 Crypto.com🟡 Gate.io🟡 Huobi🟡 Kucoin.