Economic globalism is doing a better job at stopping Russia than the US military is. Did anybody ever think we were going to put boots in Crimea? Whatever game Putin is playing at, it was never the risk of conventional warfare that scared him, and he can't play too long at this game if he wants to keep the goodwill of his people. If he went too far, it would be an embargo of Russian oil, universal across the west, that would bring him down. War would just muddle things up and damage everybody involved. I'm sure the Ukraine has no interest in being completely burned away by such a conflict.

Likewise, we wouldn't want to go to war with China. The economic repercussions would be severe in both countries. Severe enough, it is true, to most likely bring down the Chinese government. But it would also be severe enough that even the United States, if we are perfectly honest, would risk revolution. You triple the price of living and tell Americans that the Senkakus, or even Taiwan, is worth the bloodbath that would be a war against China. It isn't the cost of the military that would bring either of us to the brink - it is the cost of cutting off trade. 

That is the reality of the modern world. Militaries have some uses when dealing with entities that aren't part of the economic system, AKA rebels and terrorists (though this is debatable, since we have failed the largest of these operations time and time again), but in the post-cold war economy, where there is no alternative to the west's trade network, those countries with economies large enough to project power entirely owe their economic capacity to international trade, and their ability to function at an internal level can be completely destroyed.