@blackjack
This thing about population - both Russia and Ukraine have low birth rates and falling populations. I have family roots in several countries with birth rates that are below replacement level. Annual GDP per head in one of those countries exceeds 100,000 USD. That country has a small population. In another annual GDP per head exceeds 90,000 USD. That country has a large population. In another annual GDP per head exceeds 80,000 USD. That country has a small population. Comparative figures for Russia and Ukraine are less than 19,000 USD and less than 7,000 USD GDP per head respectively.
2 ways to contend with a falling labour pool: you can make labour more productive (which requires long term investment in education, training etc) or you can increase the labour pool by importing labour. West Germany had its Gastarbeiter (guest worker) system for many years, whereby foreigners could live and work in the country for many years but would eventually return to their home country. Another option is immigration on a permanent basis.
Countries with a culture that dislikes immigrants have a problem. Countries with political systems that reduce freedoms may have problems attracting foreign labour to live and work there. As a corrupt, authoritarian dictatorship run along the lines of a mafia state, Russia is not a very attractive state for foreigners to go and live in.
Increasing Russia's population by conquering other countries, eliminating the local culture and 'Russifying' the population is not the answer to a low birth rate in Russia.