Iran Contra affair involved contribution with the American trade of arms being the largest seller which faced embargo of weapons.
Explanation:
The United States of America was the arms seller to Iran since ages, but the Iranian student bombed the embassy of United States which leaded to the embargo that is, restriction of arms deal to the Iran.
The Reagan administration when gained office considered the major threat by Ayatollah Khomeini, supported the Contra rebels who were fighting against the Sandinista, posing threat to Reagan administration. So, in response Reagan supported Contra rebel and supplied arms to Iran through operation Enterprise. these all factors led to the contribution of the Iran - Contra affair.
