It is extremely easy to email the International Mathematical Union and lend your voice to calls to cancel this year’s International Congress of Mathematicians. It doesn’t even take any moral courage.
Deciding whether to take part in on-line conferences in Russia is a bit more difficult: you find yourself torn between the desire to help your colleagues and the need to make a statement, however small. In the end, though, it doesn’t matter very much which you decide to do.
Please spare a thought for those in Russia who are facing the decision whether to cancel such a meeting they are organising. The decision to cancel takes more than just moral courage; news reports suggest that any opposition, however low-key, to what the authorities are doing attracts severe retribution.
So what can we do other than express our solidarity with our colleagues?