On Thursday, Russian President Vladimir Putin wrote 18 European governments that get their natural gas from Russia to warn that unless Ukraine immediately comes up with $5 billion in advance gas payments he will reduce supplies needed next winter in Ukraine and Europe.

This was the third turn of the gas-supply screw in 10 days by the Russian government, which raised prices for gas delivered to Ukraine by 80 percent in two steps at the beginning of April because Ukraine has fallen $2.2 billion behind on its payments.

An added injury to Ukraine's troubled economy is that Russia had been paying Ukraine for its use of a naval base in the Crimea, which Russia seized from Ukraine in March. Last week the Russian parliament cancelled those payments.

The Russian move on gas supplies puts a new high price on Western efforts to put the Ukrainian economy back on its feet through loans from the International Monetary Fund and foreign aid from the United States and Europe.

If the new gas prices stick - and there is nothing the West can do about that in the short run - much of the projected Western aid to Ukraine will simply fatten the coffers of Gazprom, the state-owned Russian gas monopoly.

Mr. Putin apparently has learned a thing or two from the Russian Mafia.

He claimed, however, to be acting strictly according to contractual agreements with Ukraine dating back to 2007. Although President Putin's government has done everything it could in the past six months to cripple the Ukrainian economy, he blamed Europe for the troubled nation's problems.

Well, of course,

A G-7 summit in June in Brussels - G-8 minus Russia - will address the longer term energy strategy of Europe to counter its reliance on Russia. That will depend heavily on U.S. gas exports and the development of shale gas resources in England, Poland and elsewhere, more use of coal, and a possible return to nuclear power in Germany. Subsidies to renewable power resources are likely to be cut in the ensuing economic crunch until the new power sources suffice to cut Europe's strings to Russia.

But in the short term anything the West does to keep Ukraine from falling into Russia's clutches is simply likely to make Mr. Putin's government richer.