My understanding, Extremely simplified:

• Iran had US hostages.
• “But we need guns”.
• US wanted to buy some goodwill
• CIA wanted something untraceable cash
• CIA sold guns to Iran for cash they could then funnel into backing the Contras
• Iran accepted weapons, but took their bloody time releasing any hostages
• The agreement had basically devolved into selling weapons for no apparent advantage (Unless you’re in the CIA)
• Media learns about the ordeal
• Oliver North gets thrown under the bus as a scapegoat
• Hostages are eventually released
• fast forward a few decades, and Oliver North becomes yet another talking head for Fox News whenever something vaguely familiar to him is in the news cycle (Iran)