I don't think EU has an option here, they can't just fill 40% of the demand from other sources in a day or even in a year.
It will take time to set up an alternative supply chain without jacking the prices up.
And even if EU cuts of Russia's supply, Russian oil still got plenty of buyers(China, India, other asian countries - almost limitless).
This will only hurt EU and no one else.
In the current difficult situation, it is necessary to look at the energy needs of Europe much more broadly. For too long, the countries of Europe have tolerated energy dependence on Russia, which has constantly used it as a means of pressure on them to solve its economic and political problems. Now Russia is directly using them as weapons. With this in mind, the EU decided once and for all to abandon such dependence, even if at first they will suffer some material losses. Therefore, now there is a global reorientation of oil and gas suppliers to Europe. Europe is doing this, and doing it quite successfully. Yes, Russia will be able to supply its oil and gas to China, India and Asian countries. But the needs there are not very large, and it will need to reconfigure transport routes in the same way as Europe. But for Russia, this will mean the loss of the European market FOREVER. It will take time to set up an alternative supply chain without jacking the prices up.
And even if EU cuts of Russia's supply, Russian oil still got plenty of buyers(China, India, other asian countries - almost limitless).
This will only hurt EU and no one else.
