The Kurds have just captured the former Syrian Army Brigade 93 base, 30 Miles North of Raqaa.
This gives the Kurds the main base dominating a stretch of highway M4, the “inner” of the two Northern Highways that run East-West. This does two big things:
1. This links the Western Kurdish areas, notably Kobani, with the Eastern Kurdish areas, and Iraqi Kurdistan.
2. This closes off ISIS from Turkey in the North (channelizing them along the Euphrates River), while Regime Forces are approaching from the West.
Raqaa, the ISIS Capitol, is suddenly looking at risk.
Everyone was looking for a culminating battle over Mosul this Summer. After the Battle of Tikrit bogged down on the road to Mosul however, ISIS swept around and captured Ramadi, threatening Baghdad. Now it looks like the anti-ISIS forces are returning the favor, threatening Raqaa.
The balance of forces seems to put Raqaa at much greater risk than Baghdad.
Also ISIS will have a tough time getting fresh recruits in Syria.