False flag ? Several scenarios have been discussed by bloggers over recent years, and that not one of these has been pulled to date means that one those scenarios was being contemplated but had to be abandoned as nobody would believe any official story that Al Qaeda did it.
Neither of the administrations of the entity USrael has any idea now how to get a war going against Iran, and make Iran or some made up terrorist group look responsible for the initiating event.

I'm tipping that it's made in Israel, for if it was made in America, workers not Jewish would have wondered why there was this order totalling in excess of a 100tons when very small quantites were ever issued before at any one time, as its application is specialist clandestine military demolitions, meaning no more than a few pounds at a time.

When the towers came down, the workers not Jewish would have started to wonder, and sought ways to communicate this without betraying themselves.

Yes, Mordechai Vanunu was the sole exception who talked, and proves the point.

So, when it is ruled out that there is no place in America where nano thermite is made, then that is the moment the Jewish State dreads, which is why Iran must be nuked to draw Russia in on the side of Iran, and the Jewish State hopes that ww3 then ensues with America destroyed, and then no one there will be thinking about nanothermite and 911 and the Jewish State connection.

Mossad motto "by deception shall we wage war".