DJS - What Obama should be doing with some plausible deniability is what I stated earlier: having conversations with potential insurgent groups for the purpose of arming them. Or suggest that such conversations are going to be held. Meet force with force and present the potential for the very last thing Vlad wants.
What good has/will tough rhetoric by Obama and his administration and implimenting sanctions against Russia going to do to positively influence Putin? Talking tough and implimenting sanctions against Russia helps the US administration promote that they are doing something to American voters, and plays into Putin's plans. Putin is playing Chinese "Go" (i.e., whoever controls the most territory wins) and the US administration is playing tic-tac-toe (i.e., playing a stalemate game).
If the US wants to influence Putin, it needs to learn how to get unbiased information to Russians to overcome the Russian government spinning information to unduely influence russians and russian speakers. Putin's source of power is the Russian Govenment's control of information to russian speakers both inside Russia as well as outside of Russia and his willingness to use IMHO unethical methods (i.e, vote rigging, exporting pro-russian protestors to the Crimea, lying, etc.).
If the US wants to influence russians (and help other people governed by totalitarian governments) with minimal adverse impact for the US, then the US goverment needs to develop methods/equipment to increase information flow to Russian speakers that is not controlled by the US government.
Something as simple as convincing the Ukrainian Government to pass iron-clad legislation that guarantees basic human rights, freedom of the press, promotes teaching both Russian and Ukrainian languages in schools, and minimizes corruption would throw a small wrench into Putin's plans. Other ideas would be to provide information about how to detect and report Russian "dirty tricks", as well as distributing hand-held video equipment with satellite uplink support to Youtube and photo-voltaic/hand-crank charging capability to Ukrainians in the Ukraine and Crimea.
Putin is playing a waiting game, which is why I chose the "Go" analogy, until news organizations redirect their reporters to more sensationalistic news. Putin can do whatever he wants without the international news media present.
Peace be with you and everyone, who you love,
Robert