How? Start with a declaration of full-throated American support for Ukraine’s revolution. Follow that with a serious loan/aid package — say, replacing Moscow’s $15 billion — to get Ukraine through its immediate financial crisis (the announcement of a $1 billion pledge of U.S. loan guarantees is a good first step). Then join with the E.U. to extend a longer substitute package, preferably through the International Monetary Fund.

Secretary of State John Kerry says Russian intervention would be a mistake. Alas, any such declaration from this administration carries the weight of a feather. But better that than nothing. Better still would be backing these words with a naval flotilla in the Black Sea.

Whether anything Obama says or does would stop anyone remains questionable. But surely the West has more financial clout than Russia’s kleptocratic extraction economy that exports little but oil, gas and vodka.

The point is for the United States, leading Europe, to counter Russian pressure and make up for its blandishments/punishments until Ukraine is on firm financial footing.