Maybe I skimmed too fast, but neither link seems to mention a logistical build-up.
You can park tanks on your side of the border and talk big without a major logistical build-up. Or "just barely" cross the border in force. Or run a token few units deep into Ukraine (+/- local opposition). But to actually move large, modern military forces deep into Ukraine (the country is over 500,000 sq. km), a huge logistical build-up would be necessary.
Invasion is not a video game, where tanks & troop transports have unlimited fuel, never need spare parts, and there are big piles of ammunition (of the exact right sizes & types for Russian weapons) scattered every few km through the Ukrainian countryside.
You can park tanks on your side of the border and talk big without a major logistical build-up. Or "just barely" cross the border in force. Or run a token few units deep into Ukraine (+/- local opposition). But to actually move large, modern military forces deep into Ukraine (the country is over 500,000 sq. km), a huge logistical build-up would be necessary.
Invasion is not a video game, where tanks & troop transports have unlimited fuel, never need spare parts, and there are big piles of ammunition (of the exact right sizes & types for Russian weapons) scattered every few km through the Ukrainian countryside.