Ok We know the federation was going to blow qronos up in discovery. Well that bomb is still floating around. 2293 Klingon power is at a all time high. Klingons have pissed off the romulans aswell. So my theory is to end the Klingon threat once and for all, S31 and the Tal shir team up and are behind the destruction of praxis. The destruction and crippling would benefit both powers. They stage it as a accident though. It back fires however when the Klingons come to the federation for peace. S31 want the Klingons off the board and the romulans certainly don't want peace between the feds and Klingons. So the Tal shir provide chang with a experimental cloak and both S31 and Tal shir team up for there own reasons with the sabotaging of the kitomer accord This doesn't work and the peace was signed, with the romulans coming out the worst. Resentments simmers with the romulans with them blackmail the federation threatening to reveal all ruining there reputation. This results in the treaty of algerion with the federation agreeing to no cloaking, in exchange the romulans don't release the federation's dirty little secret plus forgoe development of the advanced cloak that was given to chang.