By committing fraud, money laundering, stealing and other russian cultural things of course. Everyone should stop doing business with russians. Forever.

Substitute "nationality X" for "Jews" to instantly recognize that tone anytime, anywhere.

They are a society manipulated heavily by propaganda, run by rich elites and pushed into an unproductive war by a political dictatorship supported by the elites. Perhaps everyone should have stopped doing business with the USA for the last few decades for the same reason.

You can creatively frame a problem any way you choose.

All countries have a problem with media, elites and politicians. We should aim to solve those problems, not cut a large chunk of the planet off. They are people too.

Mostly by migrating to other countries.

Judging by my friends' experience, they were never really popular inside the country. For those building projects aimed at internal audience, local companies were preferred for tax or legal reasons, and most of those working on international projects quickly emigrated to more sane countries.