Ukrainians welcome

The global anti-Trump insurrection is propagating the idea that a country does not have the right to discriminate against those who want to cross its borders. In Human Action, Ludwig von Mises argued that a "social order is doomed if the actions which its normal functioning requires are rejected by the standards of morality, are declared illegal by the laws of the country, and are prosecuted as criminal by the courts and the police." This statement is open to interpretation, and many manufacturers would argue that by not opening the borders to more Ukrainian workers, the Czech cabinet is inhibiting the normal functioning of the social order. Yet if we accept that we have no right to discriminate against those who want to cross borders, how can we justify giving special treatment to Ukrainians? Isn't it a form of reverse discrimination against Georgians, Moldovans, Russians, etc.? Is there any place left in today's anti-Trump world for visas and work permits?