Mohammed Salameh, one of the conspirators in the 1993 World Trade Center bombing, could not be called a mastermind.
Salameh was the first of the group to be arrested, when, lacking the money for a plane ticket out of New York, he attempted to reclaim the deposit on the rental van he had just blown up. (The two suspects who successfully fled the U.S. were the two with Iraqi connections -- mastermind Ramzi Yousef and Abdul Rahman Yasin.) Salameh's NY apartment was the center of the conspiracy operation, beginning in the spring of 1992--almost a year before the bombing took place.
Salameh's telephone record from that period shows an interesting pattern. (The phone log, obtained from the telephone company and introduced as evidence in Salameh's trial, is part of the public trial record.)
In June and early July of 1992, the phone records show a sharp spike in overseas phone calls, with 42 calls to Iraq. Salameh's phone bill rose from $128 in May to $1401 in June -- over 1000%. (On July 9 his telephone was cut off for non-payment of the bill.)
For the month of June, out of 59 overseas phone calls, almost two-thirds were calls to Baghdad. While many were just a minute or two long, suggesting he had not reached his party, nine of those calls were over ten minutes long (see table below). To the other countries (Egypt, West Germany, Jordan) there were only two or three long phone calls that month. (The June phone log can be viewed in pdf.)
Most of the 42 Iraq phone calls were to Salameh's uncle, who was employed in the PLO office in Baghdad after being arrested by Israel for terrorist activity. This was an individual who was certainly known to the Iraqi intelligence agency, and whose phone line was probably monitored.
Ramzi Yousef -- aka "Rashid the Iraqi" -- arrived in New York just two months later, using an Iraqi passport showing a journey that began in Baghdad.
Yousef met with Salameh almost immediately on his arrival in New York, suggesting that there was indeed a prior arrangement.
The lack of interest on the part of official investigators in this set of data -- clearly pointing to the possibility of Iraq's collaboration -- demonstrates the agencies' unwillingness to address the issue of state sponsorship of terrorism.
Table: Overseas phone calls in June 1992
Egypt 9 calls (3 long calls -- over 20 minutes) W. Germany 4 calls (2 long calls -- over 20 minutes) Iraq 39 calls (9 long calls -- 10 to 30 minutes) Jordan 6 calls (2 long calls -- 30 and 90 minutes) Saudi Arabia 1 call (0 long calls)
Detail of June 1992 phone log showing some of Salameh's calls to Iraq