The Wall Street Journal reports: U.S. intelligence agencies believe there is a strong possibility the Assad regime will use chemical weapons on a large scale as part of a last-ditch effort to protect key Syrian government strongholds if Islamist fighters and other rebels try to overrun them, U.S. officials said.

Analysts and policy makers have been poring over all available intelligence hoping to determine what types of chemical weapons the regime might be able to deploy and what event or events might trigger their use, according to officials briefed on the matter.

Last year, Syrian President Bashar al-Assad let international inspectors oversee the removal of what President Barack Obama called the regime’s most deadly chemical weapons. The deal averted U.S. airstrikes that would have come in retaliation for an Aug. 21, 2013, sarin-gas attack that killed more than 1,400 people.

Since then, the U.S. officials said, the Assad regime has developed and deployed a new type of chemical bomb filled with chlorine, which Mr. Assad could now decide to use on a larger scale in key areas. U.S. officials also suspect the regime may have squirreled away at least a small reserve of the chemical precursors needed to make nerve agents sarin or VX. Use of those chemicals would raise greater international concerns because they are more deadly than chlorine and were supposed to have been eliminated.

The intelligence is “being taken very seriously because he’s getting desperate” and because of doubts within the U.S. intelligence community that Mr. Assad gave up all of his deadliest chemical weapons, a senior U.S. official said.

Syrian officials in Damascus and New York didn’t respond to repeated requests for comment. The Syrian regime has denied using chemical weapons of any kind, disputing allegations made by the U.S. and other Western governments.

Any large-scale use of chemical weapons would exacerbate the dilemma the Syria conflict poses for the Obama administration. Mr. Obama has long called for Mr. Assad to step down, given his crackdown on opposition groups and the brutality of what became an all-encompassing civil war.

But U.S. officials say they don’t want his departure to create a security vacuum in areas controlled by the regime, allowing Sunni militants affiliated with Islamic State or the al Qaeda-linked Nusra Front to seize more territory. The U.S. officials are concerned that chemical weapons could fall into militants’ hands.

A new intelligence analysis suggests Mr. Assad could use those chemicals as a weapon of last resort to protect key installations, or if the regime felt it had no other way to defend the core territory of its most reliable supporters, the Alawites.

The analysis underlines what U.S. officials describe as growing signs of the Assad regime’s desperation on the battlefield.

Islamic State militants and competing rebel forces, some aligned with al Qaeda and others backed by the Central Intelligence Agency, have been whittling away at territory controlled by the regime, leaving critical military bases and supply lines vulnerable, particularly in the country’s northeast and south.

The regime’s weakness was apparent during recent defeats in the northwest province of Idlib and the city of Palmyra. Regime forces withdrew quickly rather than fight a prolonged battle, according to rebel commanders and U.S. officials. The regime controls only about one-quarter of the country, with the rest held by Islamic State, various opposition rebels and Kurdish groups, according to monitoring groups and diplomats. [Continue reading…]