In the trenches of eastern Ukraine, Ivan Skuratovskyi's calm verges on numbness — even after a sniper's bullet recently killed one of the 50 or so men under his command. AP Domestic Story HighlightsU.S. officials estimate the invasion could cause major loss of life and injury. Concerns that Russia's invasion will prompt a refugee crisis have worried world leaders for months. Russia's incursion could make other NATO countries nervous, especially former Soviet Baltic states. President Vladimir Putin ignored months of intensifying warnings by President Joe Biden and other Western leaders that Moscow would face "swift and severe costs" if Russia invaded Ukraine.