There are a long series of USA wars which were started over some surprisingly fortuitous "attack" by some supposed foreign party. ;-) The sinking of the Maine in Havana Harbor was a spectacular example. God knows why the ship blew up, but the least likely candidate for causing it to do so was the Spanish! They were desperate to avoid war with the USA...a war they could only end up losing. Yet the Spanish got the blame for it in the American media, of course, and the war went ahead.

The sinking of the Lusitania was the best excuse in WWI. The ship was probably carrying munitions illegally, and it was probably deliberately exposed to extreme risk by the German U-boats in hopes that it would be sunk, but they wouldn'd have told anyone about that, would they? In that case it would have been the British admiralty who were the primary schemers in the matter, not the USA.

Then there were the supposed attacks on the US fleet by North Vietnam in the Tonkin Gulf...which enabled Lyndon Johnson to pass a resolution putting massive USA forces into Vietnam.

Those attacks were a complete fiction. They never happened. But American media bought it, and Congress responded accordingly.

Then there was FDR's need to somehow get the USA into WWII, despite a public and a Congress who didn't want to go to war. So he put an embargo on Japan's overseas sources of oil and steel....which absolutely guaranteed that Japan would go to war within a year or less. I think Roosevelt was probably shocked and horrified by the tremendous amount of damage the unexpectedly capable Japanese Navy did at Pearl Harbor when the war came...I doubt he thought they would hit Pearl Harbor at all...but he did get his war. Mission accomplished.

Another example: The American people were ambivalent about whether or not to go to war over Saddam's invasion of Kuwait...UNTIL they heard about the Iraqi army killing Kuwaiti babies by taking them out of hospital incubators! The story was completely untrue. But it was believed by everyone at the time, and it was reported even by Amnesty International, who later apologized for having unwittingly spread disinformation.

The American people, like people in pretty much any nation, do not particularly want to fight a war unless it becomes unavoidable. Then they go off patriotically and fight it.

The people in the PNAC needed a casus belli to get the American people onside for wars in the Middle East and central Asia. It had to be done somehow. I can think of no better way of getting it done than to either directly arrange....or indirectly enable someone else to carry out a terrorist attack like the one on 911.

Matter of fact, I keep wondering when and if they'll arrange for something similar or even worse to justify a full scale attack on Iran...possibly even using "tactical" nuclear weapons. I shudder to think of it, but there is nothing these people might decide to do which would surprise me.