The "buffer zone" through Syria's northern Idlib province, negotiated by Russia and Turkey to forestall an Assad regime offensive on the opposition-held portion of the province, officially takes effect this week. Rebels began withdrawing heavy weapons from the zone at the start of the month, but said that fighters are remaining. Fighters from designated "radical terrorist groups"—primarily Hayat Tahrir al-Sham (HTS)—are supposed to withdraw entirely from the zone. HTS initially said it would comply on a "de facto" basis, but the zone is being implemented despite the fact that a deadline has been missed for withdrawal of all its fighters. The zone, some 20 kilometers wide, stretches from Latakia to Aleppo, through Idlib and portions of Hama province. (See map.) (Qantara, Oct. 17; AFP, Oct. 10; BBC News, Oct. 8; EA Worldview, Oct. 7) But Bashar Assad insisted that the so-called "demilitarized zone" is temporary. Addressing the central committee of his Baath Party, Assad reiterated his pledge to retake "every inch" of Syrian territory: "This province and other Syrian territory remaining under the control of terrorists will return to the Syrian state." (EA Worldview, Oct. 8)

Iran, which has significant forces fighting in Syria, began the month by firing a volley of medium-range ballistic missiles across Iraq and into Syria, apparently striking an ISIS base in retaliation for last month's deadly attack in Avhaz. (NYT, Oct. 1)