Americans against war should know that Washington's neoconservatives are busily fanning the flames of a confrontation with Russia over Ukraine.  But there's more than this to the story. A different, also somewhat behind-the-scenes group passionately believes that the breakup of the Soviet Union didn't go far enough, that Russia itself must be ripped to shreds.  Motivations for pursuing a scorched earth objective vary widely, from an inherited ethnocentric hatred to ideological fervor to plain old greed, but for descriptive purposes we may label such true believers the neoliberals. At the moment they are ascendant.
When experts on international relations correctly point out that a country like Russia has vital interests in its near abroad,  that's not the whole story then, either. The Ukraine crisis is not exactly about so-called international law versus realpolitik dominance, as it's usually portrayed by the mass media. Factoring in the influence of both the neoconservatives and the neoliberals, what we see is much less than what we're about to get.
Neither Washington nor Moscow have made the stakes clear. Surprisingly — and disconcertingly — even their propaganda shies away (though not completely on the U.S. side) from acknowledging a threat of Russian dismemberment. Logically, what's missing indicates that both sides are in deadly earnest but whether it's deliberate or not we have a critical, ongoing failure to communicate that adds to the dangers of a showdown between two nuclear armed powers.
From the Kremlin's perspective, the unseemly haste with which Washington recognized those Ukrainians behind what could only objectively be described as a violent coup sends an unmistakable signal that Washington would be delighted were similar events to unfold in Moscow. Washington's subsequent, absolutely uncompromising mendacity about its own role in the coup makes things worse. Russia, however, is in an awkward position. To admit an existential danger appears weak. To do nothing appears almost helpless. The Kremlin had to act without any good choices.
If Russia's imminent annexation of Crimea were the sum total of this crisis it would not yet be too late to find a diplomatic resolution, given a willingness to try. Lots of paths are conceivable, including some kind of indemnity to Ukraine, greater Crimean autonomy, assurances to Russia of Ukrainian neutrality, etc., etc. Both sides still have plenty of room to back up.
If, however, as argued here, the crisis is really about Moscow's resistance to a Washington led juggernaut of regime change directed haphazardly but nonetheless mercilessly against those states who unwisely, in Washington's judgment, refuse to permit the western financialization of their assets, and specifically a Washington led crusade of national minority liberation across Russia's vast lands, the possibilities for constructive dialogue are vanishingly small. Washington, thinking that Russia is now ripe for the picking, has, per the Bush lexicon, 'misunderestimated' the Kremlin's ability to withstand pressure.
Turning Russia into an overt adversary is stupid for a host of reasons, not least of which is that, up to now, Russia has played a very constructive role in helping keep the U.S. out of trouble, e.g., away from interventionist solutions in Syria and in Iran, and arguably elsewhere too, like in North Korea. Losing Russian cooperation in general multilateral affairs is not a trivial matter, nor is the potential fallout from non-cooperation on specific issues regarding nuclear weapons. Perhaps worst of all, a long-term adversarial relationship could tilt important parts of the rest of the world into an anti-U.S. camp. Riding high, enamored of its own rhetoric, Washington doesn't understand the danger, but the danger is real.
Nor should Americans uncritically accept the silliness spouted by certain political innocents in Kiev. For the moment there may be a faction in western Ukraine that wants closer ties to the European Union but once those Ukrainians realize that all they're being offered is a repeat of Greek style austerity and/or get to experience it for themselves, the bloom will be off the rose. How likely will Americans then be to pick up the tab?
This crisis is far from over. Indeed, it has barely begun.
 See Robert Parry, "Neocons Have Weathered the Storm," Consortiumnews.com, March 14, 2014.
 See, for example, Paul A. Goble's blog.
 See John J. Mearsheimer, "Getting Ukraine Wrong," the New York Times, March 13, 2014.