The cost of the American military campaign against ISIS likely has passed $1 billion.
The Pentagon estimated that the U.S. air operation cost $7.5 million per day when surveillance flights began over Iraq on June 16. That estimate increased to $10 million when bombing began Aug. 8.
That alone would put the estimated cost at $937 million. On the first night of the strikes in Syria, the United States also fired 47 Tomahawk missiles, which cost more than $1 million each, higher for more advanced models.