The US military could have taken Ukraine in 1 day without losing a ship. Russia got stuck in the mud.
WTF are you even talking about? How would the US establish supply chains?
Russia had a border with Ukraine, so it was easy for them to attack. The US would have to invade from another country, like Romania or Poland. I doubt they would
let the US wage war against another peaceful country. Also, a NATO country attacking a country bordering Russia? I'm sure Russia would play the savior of Ukraine and fight the US in such situation.
As for the strongest military in the world... You must know that both countries don't fight alone. Russia is getting help from China, Iran and North Korea, not to mention puppet states like Chechnya. Without their electronics, ammunition and men Russians would have lost months ago.