Can the combined populations of Poland and Ukraine outweigh Russia’s demographic dominance?

Of all the countries of Eastern Europe, Ukraine and Poland are the only two with populations of any significant size in relation to Russia. Having declared war on Ukraine on 24 February 2022, Russia now considers Poland a threat. For its part, Poland fears that it will be one of Russia’s next targets. Faced with this situation, Poles and Ukrainians appear intent to unite against Russia, despite the friction that has existed between them since the Second World War. Will the demographic strength of the alliance between these two countries throw sufficiently dissuasive geopolitical weight against Russia, now and in the future