Islamic State Fighting Strains Pentagon Budget

President Barack Obama's expansion of airstrikes in the Middle East is creating new strains on Pentagon planners who thought the days of costly military operations in that region were over—at least for now.

The U.S. military campaign is expected to cost tens of billions of dollars in the short-term, creating new demands on a tightening Pentagon budget.

That volatile combination is certain to put renewed pressure on Mr. Obama and Congress to come together and reconsider spending caps on the U.S. defense budget that resulted from a bitter and protracted...