A Bubble That Broke the World by Garet Garrett (pg. 158)

When we began to send man power into allied countries–no, we did not charge for that. We were charged for it.

We were charged for moving American soldiers across the sea in British ships; we bought pounds sterling with dollars and paid cash for that British service. We were charged port dues for landing ships in French harbors–ships bearing our own munitions and supplies; we bought French francs with dollars and paid cash for the right to enter.