The terrorists were not from the Middle East or even Europe. Their countries of origin were in the Caribbean and South America. The group, Jamaat al-Muslimeen, is a native terrorist group which operates in Trinidad and Tobago with offshots in Guyana and other nearby former British colonies. In fact, plotter Abdul Kadir was a member of Guyana's parliament until last year.
While most Muslims in these countries are of Indian subcontinent descent, these groups have not been radicalized by Wahhabis or other related groups. Jamaat al-Muslimeen is part of a protest religious movement. The vast majority of members are of African descent who converted to a Black Muslim version of Sunni Islam. The group has been active in racist attacks against ethnic Indians. Jamaat al-Muslimeen has released statements in the past which compared the Indians which run many of the businesses in Trinidad to "corrupt Jews."
Internationally, the groups' African roots have appealed to Libyan leader Muammar al-Qaddafi. They may have also offered support to Adnan Gulshair el Shukrijumah who has been known to visit Guyana.
The Jamaat al-Muslimmen terrorist network first gained international attention during their 1990 coup attempt against the Trinidad government. After the coup attempt the group turned to organize crime, the drug trade, and general thugness. It appears the group was dreaming of bigger things and the JFK plot may have been somesort of revenge for the arrest of leader's Yasin Abu Bakr.