Osama bin Laden was a surprising proponent of the Arab spring, according to documents found after his capture and released on Thursday.

In his last private letter written just a week before his death, he said the revolutions represented a “formidable event” and a turning point in the Arab world. Before the release of the 17 letters by the US government, the revolutions were viewed as a concern for bin Laden as they could cause instability and potential western involvement in the region.

At the time of the letter, the presidents of Tunisia and Egypt had fallen to rebel uprisings.