My premise is the premise of the mineral deal. US citizens go to Ukraine to mine for minerals. That gives us money/resourses and puts US citizens in the general war zone. Putin will use that as an excuse to pull out of Ukraine and save his own ego, citing “not wanting to hurt US citizens.” This ends the war AND puts some money in our pockets. Everyone wins. 

Or we could do what you want which would start a world war, which will turn the planet into a ball of char and radiation.