Ukraine

1. Putin is a dictator.  He is the sole authority in Russia.  He has the backing of the police and the military.

2. Putin wants to, and has, expand Russia's territory.

3. The Russian people will not oppose Putin.  The memory of soviet oppression is the memory of their grandparents.  Their parents experienced peace and growing prosperity, with a lessening of oppression.  The present generation only knows growing prosperity -- because Putin doesn't let them know about anything else.  Russians do not want to lose what little they have, and so they will comply.

4. Putin threatens to use nuclear weapons if the West opposes him.  The West believes this is a credible threat.

4A.  NATO grants Ukraine immediate membership, and immediately mobilizes its forces to oppose the Russian invasion.

5.  Putin is willing to sustain hundreds of thousands of Russian casualties, a hundred thousand deaths, in order to overcome Ukraine.  

5A. Putin uses nuclear weapons against NATO. 

5B. Putin backs down, Russia is pushed back to its pre-Crimean borders.

6. The Russian people will support this because they do not know this is happening, they support him, or they fear him.

6A. NATO retaliates.  Millions die, nuclear winter, collapse of global infrastructure, widespread famine, plague.

7. Decisive military support to Ukraine is not possible because the Ukrainians do not have the training to use it -- they do not have the training to fly F-16s or launch Patriot missiles, etc.

7A. After a millennium or so the world eventually is able to support normal life with a vastly reduced population.  Things may get better thereafter.

8. The West will not impose total sanctions because they fear for9 their economies more than they oppose Putin's actions.  They believe that the citizens of the West will concede the taking of Ukraine rather than forego their material comforts.

9. Ukraine will fall.  Their leadership will escape to the West.  People will be forced to return to Ukraine because they will be pressured to by the West.

10. Ukraine will gain it's independence only when Putin dies, and Russia becomes willing to acknowledge their independence.  This may take several generations, if not longer.