Abu Nidal was a Palestinian terrorist. The Palestinians lost the war for their homeland to the Arab nation of Jordan in the September, 1969 war.The Palestinians call that war "Black September".
To avenge their loss to the Jordanian Army, the Palestinians formed the Black September terrorist group.
The Black September terrorist group specialized in hijacking airliners.
In September of 2000, a Palestinian flew his rental aircraft into a twin-engine Cessna aircraft in Florida.
In September of 2001, at least four American aircraft were hijacked and flown to their demise in at least three targeted buildings.
And now we see the 2nd most powerful Palestinian terrorist getting taken out.
Arguably, it's easier to execute an assasination operation PRIOR to the commencement of a large scale war.
Frankly, I'd take those above facts and combine them with the possibility that Iraq's harboring of Abu Nidal could get them implicated in 9/11 activities if it can be shown that Black September was responsible for 9/11. Then I'd weigh all of the above to calculate the probability that an attack on Iraq was a certain percentage more likely with each passing month...