The big advantage we have as liberal democracies is that we have a safe business environment where the rule of law prevails. As a result, we haven't seen a lot of flight of the kind that you brought up. We haven't seen a lot of that occur simply because we are very attractive as countries for businesses to operate in.
The challenge we have more as western countries is that our efforts are essentially in vain because other countries can buy up whatever the country under sanctions is trying to sell or needs to buy. This is really the unintended consequence and huge dilemma of globalization. We have countries that don't operate according to the same value standards that we, the west, espouse and that we thought other countries would espouse too, as they developed market economies with our assistance. We could say that it was arrogance to assume they would adopt the value system on the international stage. Either way, it didn't happen and now they are major players and can absorb whatever damage or harm we are trying to impose.
I don't think we need to worry that much about capital flight from our countries, but we need to worry about the effects of our sanctions on the to-be-sanctioned country. We should also remember that other countries will look at Russia and see that they didn't do too badly despite these unprecedented western sanctions because other countries stepped in and essentially blunted the harm. The other countries are going to say they're not going to be deterred by the threat of western sanctions when they want to do something that the west, thinking itself to be speaking for the global community, is trying to prevent them from doing.