Lets not forget kerry was working with the Sandanista's against Reagan.
Not only that: Ollie was on the political track. He was a real hero, photogenic and very bright. Kerry had to bring him down not just for Ortega and company, but to clear his own future path. So, most likely with intel from Ortega, Kerry launched the investigation into Iran-Contra, which also was hoped to make Carter's failures less apparent (this failed, of course).
However, Kerry lacked the juice to lead the hearings and, as a consolation prize, was given the MIA-POW brief. In this capacity, he totally sold out our men still in Vietnam and frustrated our attempts to bring back bodies of our dead. This was a one-two punch aimed entirely at obviating the US military's claim to never leave any American soldier in enemy hands.
From the second he returned home from Vietnam, Kerry never stopped trying to harm America and benefit the communists around the world, while helping himself politically w/our enemies. He is still at it.
When this election is over and Kerry is toast, I hope Ollie North will write more on the history of that incident.