He's a traitor to the cause, an infidel and a "slave" who "groveled" before US President Donald Trump. In the latest edition of its weekly newsletter, the extremist group known as the "Islamic State," or IS, didn't hold back how it really felt about Syria's new interim president, Ahmad al-Sharaa, and his meeting with Trump last week.

In fact, this sort of enmity between the IS group and the rebel group al-Sharaa once led, Hayat Tahrir al-Sham, or HTS, is not new.

Between 2012 and 2013, HTS was part of the so-called Islamic State group before switching to ally itself with al-Qaeda. Then after cutting ties with al-Qaeda in 2016, HTS spent almost a decade fighting IS in parts of the country it controlled. So the criticism of al-Sharaa's more moderate, expedient political course is not unexpected.

But there is another interesting aspect to the al-Naba text. The IS group also called on foreign fighters in Syria to defect from the current government led by al-Sharaa. Foreign fighters upset at al-Sharaa's diplomacy with the US should join IS, the group exhorted.

The al-Naba text and al-Sharaa's meeting with Trump has refocused attention on one of the interim government of Syria's toughest problems: What to do about the presence of foreign fighters in the country.

During last week's meeting, the US president pressed al-Sharaa to "tell all foreign terrorists to leave Syria" making it one of the conditions for sanctions relief. French and German envoys have made similar statements and in general, the fear is that Syria could become a haven for groups with extremist ideologies that then become active internationally.

It's hard to know exactly how many foreigners were fighting alongside HTS. There could be anywhere between 1,500 and 6,000, with many experts suggesting it's most likely a number in the........

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