Russia and the United States are at it again, this time in a hidden struggle over hydraulic fracturing.

Russia is engaged in a fight against European fracing, working along two fronts: strong-arming nations dependent on its gas and backing environmentalist groups set against it, said Keith C. Smith, former U.S. Ambassador to Lithuania and distinguished fellow in residence at the Center for European Policy Analysis.

Smith wrote about Russia’s opposition to fracing last year.  

The U.S. has played spoiler to some extent, providing relief to Western Europe through the ...