After weeks of bloody clashes and a blockade of Nagorno-Karabakh, Azerbaijan on September 19 said it had launched an "anti-terrorist operation," a major escalation in hostilities with Armenia as the breakaway region already teeters on the brink of a humanitarian crisis after being blockaded for more than eight months.The shelling started shortly after Baku accused what it called "Armenian sabotage groups" for the two separate explosions that killed four military personnel and two civilians in areas of Nagorno-Karabakh that are under the control…