Pedro Domingos

Reason: Sanctions are not an effective deterrent. Russia has learned to live with them, even if it dislikes them. Its economy is much more resilient today to them - including in part due to help from China. Moreover, it has learned to expect sanctions no matter what it does

Sanctions instituted this year for activity traditionally considered acceptable espionage - such as the SolarWinds/HolidayBear hacks - have undermined their use for deterrence as they send a signal that we will sanction Russia for everything it does

And while sanctions on oil and gas industry could be devastating to Russia economically but there is no prospect of them happening now - not with Europe freezing in the midst of a cold winter and inflation skyrocketing in US

Reason: Putin believes that his objectives are achievable with military force. The Russian military has overwhelming advantage in long range fires to easily overwhelm the Ukrainian forces within days and then push them back to the Dnieper river with infantry and armor

He is unlikely to invade Western Ukraine but can relatively easily split the country in half along the Dnieper and establish a permanent buffer zone between Europe and Russia, as well as a land bridge to Crimea

Reason: He likely believes the military cost will be low - either in initial invasion or its aftermath. Russia has decades of experience suppressing insurgencies - in Chechnya, Syria, Donbas and even Crimea

Western Ukraine would be a different story but that’s why he is not likely to cross the Dnieper. And, of course, Russia has successfully fought insurgencies in Ukraine multiple times throughout its history - 1640s, 1700s and 1920-1950s. Lots of experience there

Reason: Putin is almost 70. He knows he has about another decade in power at most. He views himself as a historical leader who has revitalized Russia economically and militarily after the devastating and humiliating 1990s