Any analysis of the fall of Enron that fails to consider the circumstances surrounding its rise to prominence in the energy industry is shallow at best and intellectually fraudulent at worst. Enron's rise to the "big time" was facilitated by a series of favorable actions by the Clinton Administration (one published report said Clinton and Company acted affirmatively on 18 of 20 Enron requests for loans, grants and legislative initiatives) and the hope that the Kyoto Treaty would be enacted giving them a monopoly in a "new energy industry". The accounting gimmicks were only an attempt to buy time until Enron got "their man" in the White House. And make no mistake about it, Al Gore was that man. Forget the Enron donations to Bush. Every serious gambler bets both sides in a horse race. Enron needed Gore. What he would not be able to produce legislatively, he would accomplish by Executive Order. Remember, "Stroke of the pen, law of the land...Kinda cool". When the election did not go Enron's way, they knew they were in trouble. Thankfully, the Bush Administration rebuffed Ken Lay's overtures. After that, Enron's officials started bailing out. They knew it was over.
In short, Enron failed because the income side was based circumstances that were not sustainable and economic/environmental assumptions that were not viable.
Shame of many for not realizing this. This is not to excuse those on Wall Street, government types at SEC, ect. who did not do their homework and expose the sham that was Enron. There is much blame to go around. However, any attempt exposing problems should start at the beginning.