Syrian army tank
Syrian army makes dramatic gains in ISIS-held desert, enters Deir ez-Zor province, is now just 90 kilometers from the encircled city.

This one has been reported for days now, but we wanted to wait and make sure it was confirmed by reliable sources: The Syrian army has (again) made dramatic gains in Syria's southern desert.

Again the Syrian forces have covered great distances in a matter of days. This time however, ISIS offered stiff resistance but the Russian-supplied Syrian army has a vast superiority in tanks which are decisive in open desert to say nothing of Russian air support. Reportedly the Russian-trained 5th Corps spearheaded the advance.

Syria battle map
These new gains place the Syrian army just 90 kilometers away from the encircled city of Deir ez-Zor—under siege since 2014. They also put it just 90 miles from the Syrian city of al-Bukamal on the Syrian-Iraqi border which was even just weeks ago still coveted by the US and US-backed rebels in al-Tanf.

Situation before:
Syria battle map
The gains also mean supply challenges will only increase for the Syrian army as its supply routes, which are vulnerable to raids and spoiling attacks, are now dramatically extended. Also the closer it actually gets to the densely-populated Euphrates valley the stiffer ISIS resistance will become.

In a sense this has been the easy part, the hardest part of the fight is still to come. Nonetheless, the fact the Syrian advance has finally symbolically crossed into Deir ez-Zor province from which except for the encircled provincial capital it has been absent for so long will be a huge boost to morale.

The relief of the city can now finally be imagined. One complicating factor for the Syrians is that they have now forged a huge salient into ISIS-held territory. It would be a great boon to their efforts if Iraqis could clear ISIS from their side of the border as well and secure the Syrians' right flank.