It was already at 11

Susan Rice in the New York Times:

Iran's destabilizing activities in the region, notably in Syria, Yemen and Lebanon, have only intensified [since May 2018].

How has anything Iran has done in Syria been worse since the US left the nuclear deal? The Syrian catastrophe has been unfolding since 2011 e.g. Susan Rice in a valedictory interview, January 16, 2017

We were able to get the Syrian government to voluntarily and verifiably give up its chemical weapons stockpile.