At about the same time President Obama began a long, defensive appearance before reporters questioning his handling of the war against the Islamic State, the Pentagon announced Monday that American warplanes had struck a group of Islamic State trucks involved in the oil-smuggling business that brings the terrorist organization hundreds of millions of dollars a year.

The strike, near Abu Kamal, in Syria, destroyed 116 fuel trucks out of nearly 300 massed in the area, according to the Pentagon. While U.S. forces engaged in the anti-Islamic State fight, Operation Inherent Resolve, have sometimes hit the Islamic State oil trucks before, Monday’s strike was “the first time that we’ve hit so many at once,” a coalition spokesman told AFP.

Obama announced the U.S. campaign against the Islamic State on Sept. 10, 2014, pledging to “redouble our efforts to cut off [Islamic State] funding.” Given that the oil-stealing business is the terrorist group’s financial lifeblood, why has it taken until now to hit the Islamic State’s oil transport capability in a significant way?