But China will never get gas that would otherwise go to Europe, it will get gas from East Siberian fields that can only ever be used for that purpose. So such sales would only come in addition to, and separately from, European sales. They will provide some measure of diversification of revenue streams to Russia, but no additional physical leverage against Europe. But as Europe does not even acknowledge that we hold an "energy (payments) weapon" against Russia, this is all irrelevant, right?

In the long run, we're all dead. John Maynard Keynes