When Terrorists Hit Terrorists!

Hurras al Din terrorist group, a main ally of Tahrir al Sham whose members are mainly foreigners. Just a while after the attack, it was found out that the attack was performed by US warplanes.
American terrorist CENTCOM in a statement said that “US forces performed a air raid against al Qaeda in Aleppo province and in this raid, al Qaeda operatives who are responsible for external attacks against U.S. citizens and innocent civilians(!) were targeted. and added, northwest Syria remains a safe haven where al Qaeda leaders actively coordinate terrorist activities, to include planning attacks throughout the region and in the West and vowed to continue to target ISIS and alQaida to prevent both groups from using Syria as a safe haven.”
 
So US also knows and confesses that northwest of Syria became the safe haven for different kinds of terrorist groups. We know, they know, but this might be a flip for those who pretend to be asleep.
 
The question is why US and West is using these terrorists against Syrian government? Why they brag, when Syria is attacking the terrorists? Why these terrorists are supported by western media?
For US they are terrorists only when they do “external attacks” and as long as they are busy with “internal attacks” and kill Muslims, they are not only terrorist but also should be supported! Note that in the statement, “external attack” was clearly mentioned.
 
What do they mean by external and internal attacks? Doesn’t it mean attack against Muslims and their lives do not mean anything for Americans?