Triesman, who was appointed the FA's first independent chairman in January 2008, was giving evidence on the first day of a department of culture, media and sport select committee inquiry into English football governance.
He painted a bleak picture of the FA's administrative procedures and its working relationship with other football bodies, in particular the Premier League.
"Trying to describe how all the bodies have completely different approaches and things fall through the gaps of those approaches, is very difficult," Triesman said.
"When you try to describe that to football supporters it becomes almost impossible.
"It is a thoroughly unsatisfactory system with the key consequence being that the FA itself, in my judgement, apart from on-field discipline, has backed out of regulating altogether."
Triesman said that the previous Government's attempt to investigate football governance was undone by the unwillingness of the Premier League to work together with the FA and the Football League in a united response.
"The Premier League produced its own response... I thought that was a grave disappointment," he said, and produced for the committee a copy of the FA's recommendations that were never presented.
He was also unhappy about the way Premier League chairman Dave Richards acted to get his way.
"My experience is he will put his point politely in board meetings but discussions outside are extremely aggressive discussions, really aggressive discussions, points are made in a very colourful way. I wouldn't use that language."
Triesman resigned as chairman of England's 2018 World Cup bid last May after a newspaper sting but said the bid started on "what turns out to be a completely false prospectus".
"When we set off on the bid there was a huge amount of encouragement from FIFA because we could do it, create tremendous returns, organise events of those kind and handle security," he said.
"Had they said at the time that the aim was to break into new territories, then I would have advised the FA board not to start in the first place.
"I think there will be a time when the contact that I and others had with members of the executive committee should be described in detail because some of the processes I don't think stand up to proper scrutiny."
The committee will sit for the next two months with a report due out later in the year.
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