Natural gas is roiling global geopolitics, but the latest news -- a bad result in Europe -- is that the tsunami is still very much solely U.S.-based.

The U.S. shale gas boom has shaken up geopolitical presumptions by challenging Russia's gas-led hold on Europe, and threatening to crush far-dirtier rival fuels such as coal around the world. The thinking has been that Europe -- specifically Poland -- might be next in unleashing big, new shale gas supplies, an event that would make life even more difficult for Russia's petro-ruler, Vladimir Putin.

But ExxonMobil yesterday announced that its Polish drilling efforts (pictured above, drilling in the eastern Polish village of Grzebowilk) thus far have failed, reports Bloomberg's Joe Carroll. Exxon, the world's largest publicly owned producer of natural gas, said two exploratory wells in eastern Poland failed to produce sufficient gas to be profitable. This comes on top of a slew of bad signs about Europe's gas prospects: Over the last two years, drilling by three wildcatters -- Lane Energy, 3Legs Resources and BNK Petroleum -- produced only small volumes in northwest Poland, Bernstein Energy said in a note to clients this morning. Last year, Shell announced similar negative results in Sweden, and in 2010 Exxon declared its Hungarian shale-gas efforts a failure. On top of this, France and Bulgaria have banned hydraulic fracturing, the method used to produce shale gas.

The Poland story may not be over -- estimates are that it has 187 trillion cubic feet of recoverable shale gas, and Warsaw is offering enticing profit terms to keep companies at the drill. Bloomberg's Carroll quotes Gianna Bern of Brookshire Advisory in Chicago:

Shale exploration is a very high-cost and high-risk business and the Polish shale market is still in its infancy. It's early in the game for Poland, and they have significant potential reserves over there.

The drumbeat of negative drilling news -- last week, the U.S. Energy Information Administration pushed down its estimate of potentially recoverable U.S. shale gas by 40 percent -- is a reality check for the irrational exuberance that's surrounded the shale gas play.

One must keep one's eye on China, which is now pushing hard to get shale-gas drilling going. As for Europe, to the degree that Poland may possess no commercially producible shale gas, the European story would shift east to Ukraine, a place whose corruption and vulnerability to Russia have kept it from tapping almost any of its gas and oil.

Which means that, at least for many, many years to come, there is unlikely to be any shale gas from Europe. It also means that the challenge to Putin and Russia's Gazprom is contained for the time being.