MADRID -- The struggle for influence in Ukraine is a game that Putin cannot afford to lose. He gained the upper hand early in the crisis with the annexation of Crimea. Now, in eastern Ukraine's Donbas region, he is shrewdly forcing a divided and risk-averse West to choose between war and accommodation.
Obama's war powers proposal justifies operations against vaguely defined "associated" people and entities. Put that together with the post-9/11 authorization for anti-Al Qaeda operations and you have a blank check to do pretty much anything, anywhere, any time against anyone who evinces admiration/sympathy/solidarity for Isis or Al Qaeda.
Even though Putin lectured Obama at length, after forcing him to come to his dacha outside Moscow, about Russia's concerns, with a very special emphasis on Ukraine, the reality that the administration had to deal not with a nice ally and potential buddy but a tough guy with very clearly defined limits did not sink in.