This is even incredibly dumb to do in war time. Imagine instead of stocks you owned egg laying chickens. The value of the chickens went up and now you have to sell your chickens to cover the unrealized gains. After selling the chickens you now have fewer chickens left. That means fewer eggs laid in the future. This is literally destroying the means of production. They will basically have to add capital controls. Dutch business owners would have to sell a part of their equity to someone and tell that investor that they are not using the raised proceeds to grow the business, but instead to pay for the tax. Bonkers, it’s like they want Russia to win.