this is a great 9 11 T-Shirt but maybe you can create a new one with the same picture and Text but with this additional Text under it (or something similar)?:
"Sponsored by Zionist Israel" or "Sponsored by the Psychopathic Regime of Israel" or "Sponsored by Mossad"
since there are a lot of T-Shirts out there who convey that 9 11 was an inside job but not that many that bring the point home that strong Israeli forces were behind it too, this could separate your Shirt from the mass off other Shirts out there and at the same time convey a message that is closer to the truth. but I think you should make it clear that not the "jews" were behind it but the Psychopathic goverment of Israel.