To avoid this onrushing disaster, with grave potential for the loss of civilian life, some compromises will need to be made. After a cease-fire, the key exchange would be for the Russians to ensure the removal of the insurgents’ military forces from the province while the West guarantees the federal autonomy of the southeast. If a new Congress of Berlin is possible, that would have to serve as a preliminary stipulation.

Unfortunately, there is little reason for thinking that the State Department is interested in pursuing a political solution; it wants a Russian defeat, as does America’s hawkish political class. Europe is rudderless, and seems more inclined to follow the Americans than undertake an independent policy under a timid German leadership. Emotionally, the shock of the air tragedy has frozen out those parts of the political brain looking toward distant consequences and possible compromises. At such moments, we tend to think, a stiff backbone is needed, not a flexible mind. I think that viewpoint holds peril for the people of Donetsk.

David C. Hendrickson is professor of political science at Colorado College. His latest book is Union, Nation, or Empire: The American Debate over International Relations, 1789-1941 (University Press of Kansas, 2009).