It's pretty standard and not exactly rocket science. First, you scenario plan for what major powers/troublesome countries may do across the globe (China to Taiwan or the Spratleys, North Korea occupying South Korean islands, etc.). Second, you come up with how you would respond to each one, coming up with a menu of options. Finally, you communicate--through your diplomatic corps--to those powers your vision for the world and your priorities.
Using this particular crisis, a Ukraine scenario is a pretty obvious one. First, you work with Ukranians sympathetic to the West. You identify who may be the best equipped to lead the country in the future. Second, you help guide the forces sympathetic to the East more toward our way of thinking, offering them carrots. Third, you make clear to the Russians that the Ukraine should be free to choose which way it wishes to go and that intervention by them--especially militarily--would be met by the most severe consequences. Economic consequences are just the beginning. Furthermore, it would not only be us, but also our allies. /QUOTE]
That's exactly what Obama did, so what's your issue?