The Syrian city of Qusayr, located south of the regional capital Homs and near the Lebanese border, has seen some of the heaviest fighting in the Syrian Civil War since government forces mounted an offensive to retake it from rebels early last month.

Hundreds of fatalities have been reported on both sides since President Bashar Assad’s soldiers, aided by militants from the Lebanese terrorist organization Hezbollah, started their attempt to reclaim the town that is situated on the highway from the capital Damascus to Homs, a hotbed of rebel activity, as well as Tartus on the Mediterranean coast, a government stronghold.

Islamist opposition fighters conquered Qusayr last year and murdered some among the city’s Christian minority, prompting thousands of them to flee across the border into Lebanon. It is estimated that more than 20,000, mainly Sunni Muslim, residents remain.

Loyalists encircled Qusayr in early May and entered the city some two weeks ago, after a bombardment by aircraft and artillery. Street fighting has continued since. The regime claims to have restored “stability” in most of the city. Opposition leaders have urged reinforcements to be sent into Qusayr but they are hampered from reaching the area by increased government and Hezbollah control of nearby overland supply routes.

Reclaiming Qusayr is essential if Assad’s regime seeks to carve out a fairly homogenous polity in the northwest of Syria which has been free or rebel activity. The majority Alawite population there tends to support the president, who is from the same sect, while Sunni insurgents control swathes of the north and east of the country — where its oil reserves are situated.

Whether Assad’s aim is to retreat into the Alawite homeland altogether, centered on the cities of Tartus in the south and Latakia in the north with an oil terminal at Baniyas in between, or secure a larger belt of territory that includes Damascus and Homs, Qusayr cannot be allowed to remain under rebel control. It sits right in the middle of the only natural corridor into the coastal province and could otherwise be used as a staging area for attacks by rebels operating and supplied out of Lebanon.

The division of Syria along sectarian lines looks more likely two years into its civil war since reports of ethnic cleansing have surfaced from towns in the an-Nusayriyah Mountains which shield the Alawite area on the coast from the Sunni provinces in the east.