ISIS fighters are one step closer to realising their prophecy, with two major conquests in a week: the strategic centres of Ramadi in Iraq's west and Palmyra in Syria's centre.

The sudden advance of ISIS militants in Palmyra saw the army there quickly routed and international concern for the safety of the precious Roman ruins mounted. The militants have previously destroyed sites in Iraq's Mosul and Tikrit they believe to be heretical. UNESCO and Syrian cultural officials issued an alarm over the protection of the ancient ruins as ISIS advanced in Palmyra. On Thursday, ISIS began posting pictures from among the ruins.

Meanwhile, civilians in the city bemoaned the lack of international attention on their plight. Once again, the Syrian people have been left to fend for themselves, caught between bloodthirsty militants of ISIS and the murderous regime of Bashar Assad.

The Free Syrian Army was nowhere to be seen, and the Syrian army – in what has become an increasingly familiar strategy – didn't put up much of a fight. After ISIS militants first moved into the city on 12 May, they quickly progressed from the north and the east, moving to the centre of town bythe 14th. The Homs governor, Talal Barazi, said reinforcements were on the way and that the situation was 'under control'. Regime planes responded with air strikes on parts of the city, terrifying civilian residents, but by last Wednesday ISIS had taken full control.

Residents told me via Skype and phone that senior army officials fled the city, leaving younger, mostly Sunni recruits from the city to the fate of ISIS. Many young men have been drafted in to the Syrian army against their will, and as forces have depleted after years of war, the recruitment age has expanded, while exemptions to service have decreased.

ISIS militants have a well established pattern of exacting revenge on those local populations they see as sympathetic to apostate regimes. In Palmyra, activist groups reported that dozens of soldiers were beheaded. One resident told me ISIS issued a statement over the loudspeaker from the mosque, instructing residents to give up any army soldiers. 'We are afraid of revenge from both sides,' said the resident, who asked not be named. He said residents were terrified of government airstrikes, barrel bombs and chlorine attacks favoured by the regime against opposition rebels.

It's not hard to see the attraction of Palmyra for ISIS. The central oasis operates as a strategic gateway to the west of the country, and links areas under ISIS control to the east with the Iraqi border. It's also a region full of gas fields, which have proved an important source of funding for the group. Assad has used Palmyra and the surrounding Tadmur region as military base, servicing the armed forces to the north and east. Among the military prizes to be claimed by ISIS are a number of munitions stores and two minor airports.

But Palmyra,  the site of the country's most treasured antiquities, also holds a sinister and important place in the county's national identity, as the site of the notorious Tadmur Prison. Thousands who were locked up in the early uprising against Bashar Assad's rule are known to have languished there for years without trial. Palmyra, therefore, has become an important symbol of the opposition movement. ISIS seized the prison on Thursday and while there is still no word on the fate of the inmates, freeing them could serve as valuable propaganda for the group.

It is difficult to understand why the Government appeared to give Palmyra up so easily. One analysis suggested by residents is that the regime, now stretched thin across all provinces in the country, is only willing to battle for territory across the strategic corridor linking Assad's Alawite heartland of Lattakia and Tartous, to Homs, and the capital Damascus, along the Lebanese border, in a sign of the further de facto partitioning of the country.

Another analysis suggested by residents says Assad stands to gain from allowing the site to fall to ISIS; the threat of the loss of the symbolic ruins could prompt many in the West to embrace Assad as 'the devil we know'.

The US is unlikely to be drawn in to air strikes against ISIS positions in Palmyra. The US strategy has proven woefully ineffective in stemming ISIS expansion in areas where there is no viable partner force on the ground.

For all the international handwringing over the fate of the ruins in Palmyra, the up to 200,000 residents there can hope for little help from the international community. Abandoned and massacred by their government, we should not be surprised when they embrace ISIS as a Sunni resistance force, the only one capable of providing any administration.

Photo by Flickr user Ed Brambley.