Russia's stated intent to protect "compatriots" who are not Russian citizens establishes a strategic doctrine for intervention in other countries. Russia used its veto power to nullify a UN Security Council resolution that would have upheld Ukraine's established borders against the Crimean referendum. Effective action to counter Russian intervention in Ukraine now lies outside the UN diplomatic machinery.
The Crimean peninsula is heavily dependent upon Ukraine for water and energy. Ukraine claims Russia has already launched an incursion into Strelkova (Strilkove) from the Crimea. The seizure of a "natural gas station" is probably a warning to Ukraine that it should not interfere with the resource links that feed Crimea. There is no evidence from open source reporting that Ukrainian military units were able or willing to repulse this incursion. This lack of resistance will embolden Russian commanders to make further incursions. The decision of one regional commander to send a combined arms task force to secure a location outside his unit's defined area of operations indicates that other Russian commanders possess similar freedom of initiative. Ukraine's options for mitigating Russian freedom of maneuver are limited. Reducing water flow from the North Crimea Canal through the Isthmus of Perekop would hurt all Crimeans and invite a Russian attempt to seize the Kakhovka Hydroelectric Power Plant that controls the Kakhovka Reservoir feeding the canal. Third Eye OSINT assesses the Kakhovka Hydroelectric Power Plant to be a critically important infrastructure node. Control of this node ensures control of Crimea.
Outside The Beltway helpfully provided three maps of Ukraine's ethno-linguistic breakdown, political leanings, and natural gas pipelines at the beginning of March 2014. Knowing where Russian sympathies are strongest in Ukraine indicates areas where pro-Russian partisans are likely to block Ukraine government actions and incite unrest. The Wikipedia article on roads in Ukraine describes their general lack of serviceability but shares little detail on routes from the Russian border into the eastern Ukrainian interior. The accompanying Wikipedia graphic on Ukraine's International E-roads identifies six routes connecting Russia and Ukraine. Knowing where the E-roads connect to the Russian interior allows understanding of where Russian armored forces may stage prior to tactical maneuvers.
Zerohedge's most recent infographics on Russian force commitments to the Ukraine theater compare what is known in Western media to what Ukrainian observers would like us to know. Zerohedge publishes geopolitical perspectives that are frequently intriguing and sometimes alarming; its perspectives need independent verification. The second infographic on that page is from former Ukrainian military officer Dmitry Tymchuk, who publishes an English-language blog for the Kyiv Post. That blog's header notes that it works closely with Voices of Ukraine, which is associated with the PR apparatus of EuroMaidan. Both graphical depictions generally match yesterday's State Department travel warning for parts of western Russia that are probable staging areas for Russian military units. Photos of Russian armored vehicles moving by rail to locations in Russia's western interior are widely available on the Web in English-language media, although I have not seen many in official Russian-language media.
Capabilities and intent indicate a most likely course of action. Unopposed Russian incursions outside of Crimea indicate the occupying force's ability to seize critical infrastructure at will. Moscow's declared interest in ensuring the safety of Russian language speakers anywhere in Ukraine is an expansive statement of intent. It is therefore very likely that Russia will launch armed incursions into eastern and southern Ukraine. The Carnegie Endowment noted that Russian forces' initiative and tactical maskirovka have succeeded in achieving dominance. Third Eye OSINT notes that this success has come partly due to very restrictive rules of engagement for Russian forces in Crimea that have blockaded Ukrainian forces in their garrisons. Pro-Russian partisans intimidating Crimeans and foreign journalists show no such restraint. It is therefore likely that Russia will continue to employ a combination of cooperative local "volunteer" provocateurs and military units under very restrictive rules of engagement to take control of Russian-leaning parts of eastern and southern Ukraine. Temporary incursions and unrest may be sufficient to exert a level of control over parts of Ukraine that offers Russia more strategic options in engaging the West.