I don't think that an truely perfect alternative was ever availible.
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Well, duh.
Are any perfect alternatives EVER available?
But the alternative in which 4,000 Americans were not killed in the Iraq War, where no Iraqis were driven into exile, where the Sunnis and Shiites managed to live nextdoor to each other in the same neighborhoods, in which the Golden Mosque was not blown up, in which maybe 20,000 US soldiers were not maimed or turned into vegetables just might have been a better one.
What it looks like is that Juniorbush, Rummy and Cheney cherry-picked intel, throwing out anything that might make invading Iraq sound like the bad, dangerous or stupid idea that it really was, and keeping all the rest. The various allies didn't want to anger the Americans by disagreeing with them, so they chose to sort of agree, but not to the point where they would send in large numbers of troops as in Iraq War I.
Juniorbush and Cheney wanted to invade Iraq the day that they were selected. 9-11 was used as their justification.
The invasion was done without proper planning, and with Rummy disagreeing with and overriding Shinsecki and any other experienced officer that disagreed with him, and the results were the ghastly botched mess we had until Pertraeus managed to have some successes.