Within a matter of days, Washington produced three snapshots of the hidden bill from the Iran war. The Pentagon signed a $22.9 billion contract to expand Tomahawk production. The Navy dispatched the USS George Washington from the Western Pacific to relieve the USS Abraham Lincoln after a punishing deployment. Then, President Donald Trump said he had scaled back military exercises with South Korea because Seoul declined to help in Iran and was not paying enough for U.S. protection.

The first two developments explain why Trump is right to demand more from America’s allies. The third shows how not to collect the bill.