They were greatly alarmed when they heard that the king had given him authority to recruit troops: The pronoun They refers to the Syrians soldiers in the fort. Since verse 7 does not specify only the Syrians, it would be helpful to indicate who is meant here by rendering this verse as follows:

• The Syrian soldiers in the fort were terrified when they learned that the king had given Jonathan authority to hire soldiers.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on 1-2 Maccabees. (UBS Helps for Translators). New York: UBS, 2011. For this and other handbooks for translators see here.