Russia's offer of Russian passports to the members of the disbanded Ukrainian security force Berkut while saying that it will move troops in to protect Russian citizens is a genuinely new wrinkle on imperialism that emerged in the 21st century. What Russia is doing in Ukraine is demonstrating that what Russia did in Georgia was not a fluke. Offering passports to minorities in neighboring countries and then invading to protect its newly minted citizens enlarges both Russia's territory and its population.
Land grabs using citizenship grants is instant colonial imperialism. Nobody seems to be treating this as a serious challenge to the existing world system. It is.
The US is cutting its military. Absent a fiscal course correction to a sustainable spending pathway, it will be cutting it again in the near future and likely will keep on cutting it for decades absent an actual attack on its territory. Who will stop Russia from further adventures?