Look at what happened in Afghanistan, the moment USA removed itself, Taliban took over and that is what we are seeing today.
That's not even close to what really happened. Taliban extremists kicked US out of the country, they even received a donation of about $100 billion worth of advanced US military equipment as the US military was escaping Afghanistan.
Sanctions didn't matter that much neither, Russian economy is still fine.
What sanctions? Everyone is buying Russian gas an oil.
The only thing that changed was that before the invasion they were paying Russia in USD and now they are paying Russia in Ruble.
Have you checked Ruble exchange rate? It has gone up to its highest value ever since 2020.