The New York Times reports: The United States and its allies have sharply increased their airstrikes against the sprawling oil fields that the Islamic State controls in eastern Syria in an effort to disrupt one of the terrorist group’s main sources of revenue, American officials said this week.

For months, the United States has been frustrated by the Islamic State’s ability to keep producing and exporting oil — what Defense Secretary Ashton B. Carter recently called “a critical pillar of the financial infrastructure” of the group — which generates about $40 million a month, or nearly $500 million a year, according to Treasury Department estimates.

While the American-led air campaign has conducted periodic airstrikes against oil refineries and other production facilities in eastern Syria that the group controls, the organization’s engineers have been able to quickly repair damage, and keep the oil flowing, American officials said. The Obama administration has also balked at attacking the Islamic State’s fleet of tanker trucks — its main distribution network — fearing civilian casualties.

But now the administration has decided to increase the attacks and focus on inflicting damage that takes longer to fix or requires specially ordered parts, American officials said.

The first evidence of the new strategy came on Oct. 21, when B-1 bombers and other allied warplanes hit 26 targets in the Omar oil field, one of the two largest oil-production sites in all of Syria. American military analysts estimate the Omar field generates $1.7 million to $5.1 million per month for the Islamic State. French warplanes struck another oil field nearby earlier this week.

The goal of the operation over the next several weeks is to cripple eight major oil fields, about two-thirds of the refineries and other oil-production sites controlled by the Islamic State, also called ISIS or ISIL. [Continue reading…]