What will happen if at the end Russia succeed in her conquest against Ukraine and take over the economy of Ukraine. That will extend the economic power of Russia no doubt and that will make Russia more powerful.
How will EU and NATO countries relate with Russia if that happens ?
Full annexation of Ukraine causes instability in Russia. 40%-50% of the people of Ukraine are pro-Russian and other favorite EU. Those Anti-Russian people will not set back so easily. There will be an insurgent and civil war like we have seen in Syria. EU countries will not only damage the Russian economy but also their economy too by putting sanctions on Russia. Germany already lifted sanctions from Russia's energy source.