"What exactly is the difference........?"
We paid for our mistake.
In 1996, the United States and Iran reached "an agreement in full and final settlement of all disputes, differences, claims, counterclaims" relating to the incident at the International Court of Justice.[8] As part of the settlement, the United States did not admit legal liability but agreed to pay US$61.8 million, ($92.9 million today), amounting to $213,103.45 ($320446 today) per passenger, in compensation to the families of the Iranian victims.
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