In this Feb. 16, 2016, file photo, Turkish artillery fire from the border near Kilis town toward northern Syria, in Kilis, Turkey. The fighting in northern Syria has huge implications in the civil war and risks erupting into a wider regional conflict. The battle for control of Aleppo involves all the major players over a prized strip of rebel-held territory near the Turkish border. AP File Photo
GAZIANTEP, Turkey鈥擜 single road, like a fragile umbilical cord, connects rebel areas of Syria鈥檚 second聽city Aleppo with international relief from Turkey.
Those who remain are stockpiling arms and supplies鈥攂racing for their redoubt to be completely blockaded by the Syrian regime.
In the Turkish city of Gaziantep, charities are preparing to send aid south of the border to a Syrian city where 250,000 to 300,000 people are still living despite the relentless violence, too poor to escape or too invested in the fighting鈥檚 outcome to run away.
READ: 鈥�500 dead鈥� in Syria regime鈥檚 Aleppo assault
鈥淭he siege by regime forces is not yet a done deal,鈥� said Assad Al-Ashi, head of the NGO Baytna Syria, adding that one road to Aleppo鈥檚 west remains open.
鈥淏ut it is under fire from all sides so it is still dangerous. It can be cut off at any moment,鈥� he said.
鈥淧reparations are in full swing to get ready for a full siege,鈥� Ashi added.
鈥淪yrian humanitarian organizations鈥攖here are around a hundred on the ground鈥攁re stockpiling everything they can inside the city.
鈥淭he local council in Aleppo has formed an emergency body to prepare for the siege. In the event of a total siege, Aleppo could last for a year, probably more,鈥� he estimated.
President Bashar al-Assad鈥檚 army began large-scale offensives against the Aleppo rebels in February, backed by an intense campaign of Russian air strikes.
READ: UN urges Turkey to open borders, end to bombing of Aleppo
Bombardment by bombardment, strike by strike, fears that the city faces complete encirclement have taken hold, with thousands of civilians displaced by the fighting.
Insurgent groups can still reach the other rebel stronghold of Idlib in the northwest. From there, the Aleppo fighters have stockpiled hundreds鈥攑erhaps even thousands鈥攐f tonnes of weapons and provisions like flour, oil, sugar and medical supplies.
鈥楴ot watertight鈥�
The siege of the southern city of Homs鈥攚here the rebels held out for three years before finally surrendering鈥攑rovides a grim example of what Aleppo could face.
鈥淏ut Aleppo won鈥檛 be like that,鈥� said Manhal Bareesh of the Syrian opposition.
鈥淭he rebel zones are much larger and better defended. They are building trenches and tunnels so they can continue to move around. The siege will never be completely watertight.鈥�
Many hospitals and clinics, often targeted by air strikes to demoralise civilians and fighters, have been moved to basements, as have some schools.
鈥淒octors who had to leave, left. Those who stayed know what鈥檚 coming and are willing. It鈥檚 their choice,鈥� he said.
One city keeps popping up in conversations: Grozny, the capital of Chechnya. The city was completely destroyed by Moscow in the 1990s during the Chechen wars.
鈥淩ight now, everything depends on Moscow,鈥� Ashi said of Assad鈥檚 key international ally.
鈥淏ashar is ready to destroy everything if necessary to secure a victory in Aleppo. But he doesn鈥檛 have the means, nor the soldiers to do it. You鈥檇 have to obliterate it, like Grozny. Will the Russians agree to that?鈥�
Ashi said he expects the front to remain open for 鈥�20, or 30 years鈥�, adding that the rebels are ready to do whatever is necessary to keep it open, and that the Turks are ready to help.
The International Committee of the Red Cross (ICRC) said Friday that it was 鈥渄eeply alarmed鈥� by the situation in Aleppo.
And after a massive exodus of refugees now stuck at the Turkish border, Amnesty International criticised Turkey for refusing entry to some injured Syrian civilians fleeing the fighting, describing its policy as 鈥渁ppalling鈥�.
Bareesh said he believes Russia will continue its strikes, even to the point of Grozny-level destruction.
鈥淚f the UN, the US and the rest of the world look away, there is no hope,鈥� he added.