Loans create deposits. When a bank issues a loan, it creates the equivalent deposit automatically.
That's the loan department of a bank.
The treasury department of a bank then persuades the ultimate holders of those deposits to swap them for bank bonds and equity, which then fulfils the 'capital requirements' of regulation.
In other words lending is not restricted by quantity, but by price. Banks are never constrained by regulations on the liability side. All they do is change the price of money.
The way Russia will pay people is by the Russian Treasury paying whoever needs paying in Roubles. That creates an automatic overdraft for the Russian Treasury at the Russian central bank that balances the additional commercial reserves the transfer journal creates. And that's all they need to do. They don't even need to pay interest if they don't want to.
How do I know this? Because that's how the UK's Bank of England and Treasury works, which along with colleagues I have documented in very great detail[0]
People in Russia will accept those roubles because Putin will tax them in roubles and throw them in gulags if they don't pay. As long as he taxes enough, there won't be any inflation.
That's all the Russian authorities need to do to ensure a flow of real goods and services towards the Russian war machine. They are self-sufficient in everything that matters, and anything else he needs he can source via China in exchange for oil, gas and other natural resources.
What would be really entertaining is if Russia demanded that other countries settle their gas bill in Roubles. Then confiscate foreign holdings of them. How long then before the EU sues for peace?
Swift is a glorified email system between banks, and can replaced by a different email/MQ system between banks. Correspondence banking existed for centuries before we had computers. The excessive excitement over Swift belies the reality of how transactions are settled by banks on the ground.
Stopping Putin transacting in other currencies is irrelevant. Since the world is stopping selling stuff to Russia he will have no bills in other currencies to settle. The only people that suffer are those providing the transaction services in the West, who will earn less and may have to lay off workers.
Putin doesn't need our money. He has his own.
[0]: https://gimms.org.uk/2021/02/21/an-accounting-model-of-the-u...