It is very likely that this letter was not sent by Seyid Riza, but by a Kurdish revolutionary from Dersim who took refuge in Syria, named Nuri Dersimi. He was trying to get support for the Kurdish nationalist cause from Western powers (which he didn't get). The Turkish state used the letter to incriminate Seyid Riza of rebelling against the state but never proved that the letter was written by him. English archives supposedly show that the signature underneath was from Nuri Dersimi.