Why explosions on oil and gas pipelines are not repeated?

[rupol2000]

Perhaps they have increased protection, and are constantly patrolling the fuel lines in Europe?
It is strange that these actions have been stopped, because this is an easy and effective way to wage an underground war.
Fuel lines are also easily vulnerable from the submarine

 

[DudleySmith]

Pipelines are easily repaired quickly, plus there are 100's of thousands of miles of them in the U.S. alone., and trains and trucks can move product as well.

The British funded and suplied over 200,000 partisans behind German lines on the eastern front for years; they destroyed a lot of trains and bridges but nor more than the air forces and artillery did with far fewer units and people. Blowing them would be annoying but not permanently crippling and sooner or later the saboteurs would be tracked down, especially these days.