POTUS shares the general opinion in the US that we run the world. In pursuit of that belief he intends to sanction Russia in various ways including the punishment of private Russian capital and capitalists in the belief that rich people in Russia will force Putin to obey us.
What will happen is that Russia will match us rung by rung in going up an escalatory ladder of sanctions; visas, seizures, etc.
Russia will certainly annex the Crimea.
How far is Obama prepared to go up that ladder? Somewhere near the top lies a transition to military red lines and the possibility of a nuclear exchange that would destroy both Russia and the US. pl