In Clark's book Winning Modern Wars, published in 2003, he describes his conversation with a military officer in the Pentagon shortly after 9/11 regarding a plan to attack seven countries in five years:
"As I went back through the Pentagon in November 2001, one of the senior military staff officers had time for a chat. Yes, we were still on track for going against Iraq, he said. But there was more. This was being discussed as part of a five-year campaign plan, he said, and there were a total of seven countries, beginning with Iraq, then Syria, Lebanon, Libya, Somalia, Sudan and finishing off Iran."
https://en.wikipedia.org/wiki/Wesley_Clark