US intelligence thinks Assad could use chemicals on a massive scale 'because he's getting desperate'

Despite assurances that the regime of Syria's Bashar al-Assad had given up the country's stockpile of chemical weapons, US intelligence suspects that the regime could use large-scale chemical weapons attacks to maintain control of government strongholds, The Wall Street Journal reports.

US officials believe the Assad regime has created a new type of chemical bomb filled with chlorine and obtained the chemicals needed to make nerve agents sarin or VX, according to the Journal. Assad agreed to give up his chemical arsenal after a 2013 sarin attack that killed 1,400 people, averting the threat of US-led airstrikes.

Hamish de Bretton-Gordon, a former commanding officer of the British army's chemical-weapons unit, told the Journal: "Even if the regime had only one ton of VX left, that would be enough to kill thousands of people."

A US official told the Journal that Assad is "getting desperate" in its bid for control of key areas of Syria.

This might even include a tacit, occasional alliance with the Islamic State terror group (also known as ISIS, ISIL, or Daesh), which is also fighting for control of Syria.

ISIS has been pushing toward Aleppo in Syria, seemingly aided by air strikes from the Assad regime. Assisting ISIS in its fight against rebel forces helps get rid of the more moderate opposition fighters who threaten Assad's power. While the rebels focus mostly on taking down the Assad regime, ISIS fights both the rebels and regime forces.

Though US officials are aware of this and have publicly condemned Assad and vowed to wipe out ISIS, the Obama administration seems reluctant to intervene too much in the Syrian civil war.

Experts have suggested that President Barack Obama's determination to secure a nuclear deal with Iran, Syria's main ally in the Middle East, most likely informed his decision to refrain from getting too involved in Syria.

US officials also worry about a security vacuum forming if the Assad regime was forced out of certain areas that would then be vulnerable to a takeover by ISIS or the Al Qaeda affiliate Jabhat al-Nusra, according to the Journal. If the Assad regime does have the chemical weapons the US thinks it has, they could then come under control of the militants.

The factions competing for control of territory Syria have made the Assad regime increasingly desperate, the Journal notes, and Assad might use the chemical weapons in a last-ditch effort to protect key areas.